Vyxal, 32 bytes
0f»#tṪİ□しろいしかく»6τʀ»3¡s↳‡∴»+/τ+Jf18vḋ›i
Port of 05AB1E.
How?
0f»#tṪİ□しろいしかく»6τʀ»3¡s↳‡∴»+/τ+Jf18vḋ›i
0f # Push ten converted to a list of digits: [1, 0]
»#tṪİ□しろいしかく» # Push compressed integer 145680302990
6τ # Convert to base-64 as list: [2, 7, 43, 14, 16, 14, 14]
ʀ # Convert each to a range [0, item]
»3¡s↳‡∴» # Push compressed integer 180810357611003
+/τ # Convert to base-148 as list: [17, 30, 48, 129, 93, 147, 111]
+ # Add the values in these two lists at the same positions
J # Join the [1, 0] and this list together
f # Flatten this list
18vḋ # Divmod each by 18
› # Increment each
i # 0-based index the input into this list
Vyxal, 32 bytes
0f»#tṪİ□しろいしかく»6τʀ»3¡s↳‡∴»+/τ+Jf18vḋ›i
Port of 05AB1E.
How?
0f»#tṪİ□しろいしかく»6τʀ»3¡s↳‡∴»+/τ+Jf18vḋ›i
0f # Push ten converted to a list of digits: [1, 0]
»#tṪİ□しろいしかく» # Push compressed integer 145680302990
6τ # Convert to base-64 as list: [2, 7, 43, 14, 16, 14, 14]
ʀ # Convert each to a range [0, item]
»3¡s↳‡∴» # Push compressed integer 180810357611003
+/τ # Convert to base-148 as list: [17, 30, 48, 129, 93, 147, 111]
+ # Add the values in these two lists at the same positions
J # Join the [1, 0] and this list together
f # Flatten this list
18vḋ # Divmod each by 18
› # Increment each
i # 0-based index the input into this list