#MS Excel formulas, (削除) 163 (削除ここまで)(削除) 151 (削除ここまで)(削除) 150 (削除ここまで) 143 bytes Not exactly a programming language, but here it goes...

0: -Z9 (03 bytes)
1: N(TRUE) (07 bytes)
2: TYPE(T(Z9)) (11 bytes)
3: TRUNC(PI()) (11 bytes)
4: TYPE(TRUE) (10 bytes)
5: ODD(PI()) (09 bytes)
6: FACT(PI()) (10 bytes)
7: ODD(PI()+PI()) (14 bytes)
8: EVEN(PI()+PI()) (15 bytes)
9: TRUNC(PI()*PI()) (16 bytes)
10: EVEN(PI()*PI()) (15 bytes)
42: EVEN(CODE(-PI())-PI()) (22 bytes)

PI() is used in most cases as it is the shorter way (that I am aware of) to introduce a numeric value without using a number or string literal. N converts various things (incl. booleans) to numbers, and T converts various things to text. TYPE returns 2 for a text argument and 4 for a boolean argument. TRUNC discards fractional part (i.e. rounds positive numbers down), EVEN rounds up to the next even number, and ODD rounds up to the next odd number. CODE(-PI()) is the ASCII code of the first character of the conversion to text of -π, i.e. 45 (for "-").

EDIT: Removed equal signs from the byte count (-12!) - as pointed out by NBz in the comments, they are not supposed to be included.

EDIT 2: Assuming the rest of the worksheet is empty, it is possible to use a reference to an empty cell as zero (again, suggested by NBz) provided that we include a minus sign (or use it in other numeric expression) to resolve type ambiguity.

MS Excel formulas, (削除) 163 (削除ここまで)(削除) 151 (削除ここまで)(削除) 150 (削除ここまで) 143 bytes

Not exactly a programming language, but here it goes...

0: -Z9 (03 bytes)
1: N(TRUE) (07 bytes)
2: TYPE(T(Z9)) (11 bytes)
3: TRUNC(PI()) (11 bytes)
4: TYPE(TRUE) (10 bytes)
5: ODD(PI()) (09 bytes)
6: FACT(PI()) (10 bytes)
7: ODD(PI()+PI()) (14 bytes)
8: EVEN(PI()+PI()) (15 bytes)
9: TRUNC(PI()*PI()) (16 bytes)
10: EVEN(PI()*PI()) (15 bytes)
42: EVEN(CODE(-PI())-PI()) (22 bytes)

PI() is used in most cases as it is the shorter way (that I am aware of) to introduce a numeric value without using a number or string literal. N converts various things (incl. booleans) to numbers, and T converts various things to text. TYPE returns 2 for a text argument and 4 for a boolean argument. TRUNC discards fractional part (i.e. rounds positive numbers down), EVEN rounds up to the next even number, and ODD rounds up to the next odd number. CODE(-PI()) is the ASCII code of the first character of the conversion to text of -π, i.e. 45 (for "-").

EDIT: Removed equal signs from the byte count (-12!) - as pointed out by NBz in the comments, they are not supposed to be included.

EDIT 2: Assuming the rest of the worksheet is empty, it is possible to use a reference to an empty cell as zero (again, suggested by NBz) provided that we include a minus sign (or use it in other numeric expression) to resolve type ambiguity.

#MS Excel formulas, (削除) 163 (削除ここまで) (削除) 151 (削除ここまで) 150 bytes Not exactly a programming language, but here it goes...

0: N(FALSE) (08 bytes)
1: N(TRUE) (07 bytes)
2: TYPE(T(PI())) (13 bytes)
3: TRUNC(PI()) (11 bytes)
4: TYPE(TRUE) (10 bytes)
5: ODD(PI()) (09 bytes)
6: FACT(PI()) (10 bytes)
7: ODD(PI()+PI()) (14 bytes)
8: EVEN(PI()+PI()) (15 bytes)
9: TRUNC(PI()*PI()) (16 bytes)
10: EVEN(PI()*PI()) (15 bytes)
42: EVEN(CODE(-PI())-PI()) (22 bytes)

PI() is used in most cases as it is the shorter way (that I am aware of) to introduce a numeric value without using a number or string literal. N converts various things (incl. booleans) to numbers, and T converts various things to text. TYPE returns 2 for a text argument and 4 for a boolean argument. TRUNC discards fractional part (i.e. rounds positive numbers down), EVEN rounds up to the next even number, and ODD rounds up to the next odd number. CODE(-PI()) is the ASCII code of the first character of the conversion to text of -π, i.e. 45 (for "-").

EDIT: Removed equal signs from the byte count (-12!) - as pointed out by NBz in the comments, they are not supposed to be included.

#MS Excel formulas, (削除) 163 (削除ここまで) (削除) 151 (削除ここまで) (削除) 150 (削除ここまで) 143 bytes Not exactly a programming language, but here it goes...

0: -Z9  (03 bytes)
1: N(TRUE) (07 bytes)
2: TYPE(T(Z9)) (11 bytes)
3: TRUNC(PI()) (11 bytes)
4: TYPE(TRUE) (10 bytes)
5: ODD(PI()) (09 bytes)
6: FACT(PI()) (10 bytes)
7: ODD(PI()+PI()) (14 bytes)
8: EVEN(PI()+PI()) (15 bytes)
9: TRUNC(PI()*PI()) (16 bytes)
10: EVEN(PI()*PI()) (15 bytes)
42: EVEN(CODE(-PI())-PI()) (22 bytes)

PI() is used in most cases as it is the shorter way (that I am aware of) to introduce a numeric value without using a number or string literal. N converts various things (incl. booleans) to numbers, and T converts various things to text. TYPE returns 2 for a text argument and 4 for a boolean argument. TRUNC discards fractional part (i.e. rounds positive numbers down), EVEN rounds up to the next even number, and ODD rounds up to the next odd number. CODE(-PI()) is the ASCII code of the first character of the conversion to text of -π, i.e. 45 (for "-").

EDIT: Removed equal signs from the byte count (-12!) - as pointed out by NBz in the comments, they are not supposed to be included.

EDIT 2: Assuming the rest of the worksheet is empty, it is possible to use a reference to an empty cell as zero (again, suggested by NBz) provided that we include a minus sign (or use it in other numeric expression) to resolve type ambiguity.

#MS Excel formulas, (削除) 163 (削除ここまで) 151 bytes Not exactly a programming language, but here it goes...

0: PI()-PI() (09 bytes)
1: N(TRUE) (07 bytes)
2: TYPE(T(PI())) (13 bytes)
3: TRUNC(PI()) (11 bytes)
4: TYPE(TRUE) (10 bytes)
5: ODD(PI()) (09 bytes)
6: FACT(PI()) (10 bytes)
7: ODD(PI()+PI()) (14 bytes)
8: EVEN(PI()+PI()) (15 bytes)
9: TRUNC(PI()*PI()) (16 bytes)
10: EVEN(PI()*PI()) (15 bytes)
42: EVEN(CODE(-PI())-PI()) (22 bytes)

PI() is used in most cases as it is the shorter way (that I am aware of) to introduce a numeric value without using a number or string literal. N converts various things (incl. booleans) to numbers, and T converts various things to text. TYPE returns 2 for a text argument and 4 for a boolean argument. TRUNC discards fractional part (i.e. rounds positive numbers down), EVEN rounds up to the next even number, and ODD rounds up to the next odd number. CODE(-PI()) is the ASCII code of the first character of the conversion to text of -π, i.e. 45 (for "-").

EDIT: Removed equal signs from the byte count (-12!) - as pointed out by NBz in the comments, they are not supposed to be included.

#MS Excel formulas, (削除) 163 (削除ここまで) (削除) 151 (削除ここまで) 150 bytes Not exactly a programming language, but here it goes...

0: N(FALSE) (08 bytes)
1: N(TRUE) (07 bytes)
2: TYPE(T(PI())) (13 bytes)
3: TRUNC(PI()) (11 bytes)
4: TYPE(TRUE) (10 bytes)
5: ODD(PI()) (09 bytes)
6: FACT(PI()) (10 bytes)
7: ODD(PI()+PI()) (14 bytes)
8: EVEN(PI()+PI()) (15 bytes)
9: TRUNC(PI()*PI()) (16 bytes)
10: EVEN(PI()*PI()) (15 bytes)
42: EVEN(CODE(-PI())-PI()) (22 bytes)

PI() is used in most cases as it is the shorter way (that I am aware of) to introduce a numeric value without using a number or string literal. N converts various things (incl. booleans) to numbers, and T converts various things to text. TYPE returns 2 for a text argument and 4 for a boolean argument. TRUNC discards fractional part (i.e. rounds positive numbers down), EVEN rounds up to the next even number, and ODD rounds up to the next odd number. CODE(-PI()) is the ASCII code of the first character of the conversion to text of -π, i.e. 45 (for "-").

EDIT: Removed equal signs from the byte count (-12!) - as pointed out by NBz in the comments, they are not supposed to be included.