Factor + lists.lazy math.primes.factors math.unicode, 69(削除) 69 (削除ここまで) 65 bytes
[ 1 lfrom [ divisors [ length 1 ] keep n/v sumΣ /mod integer?0 = ] lfilter ]
It's a quotation that returns an infinite lazy list of the harmonic divisor numbers.
Explanation
1 lfroman infinite lazy list of natural numbers[ ... ] lfilterselect numbers for which the quotation returnstruedivisorsget the divisors of a number (e.g.6 divisors->{ 1 2 3 6 })[ length 1 ] keep(e.g.{ 1 2 3 6 } [ length 1 ] keep->4 1 { 1 2 3 6 })n/vdivide number by vector (e.g.1 { 1 2 3 6 } n/v->{ 1 1/2 1/3 1/6 })sumΣtake the sum/divide forming a rational numberinteger?mod 0 =is it an integera divisor?
Factor + lists.lazy math.primes.factors, 69 bytes
[ 1 lfrom [ divisors [ length 1 ] keep n/v sum / integer? ] lfilter ]
It's a quotation that returns an infinite lazy list of the harmonic divisor numbers.
Explanation
1 lfroman infinite lazy list of natural numbers[ ... ] lfilterselect numbers for which the quotation returnstruedivisorsget the divisors of a number (e.g.6 divisors->{ 1 2 3 6 })[ length 1 ] keep(e.g.{ 1 2 3 6 } [ length 1 ] keep->4 1 { 1 2 3 6 })n/vdivide number by vector (e.g.1 { 1 2 3 6 } n/v->{ 1 1/2 1/3 1/6 })sumtake the sum/divide forming a rational numberinteger?is it an integer?
Factor + lists.lazy math.primes.factors math.unicode, (削除) 69 (削除ここまで) 65 bytes
[ 1 lfrom [ divisors [ length 1 ] keep n/v Σ mod 0 = ] lfilter ]
It's a quotation that returns an infinite lazy list of the harmonic divisor numbers.
Explanation
1 lfroman infinite lazy list of natural numbers[ ... ] lfilterselect numbers for which the quotation returnstruedivisorsget the divisors of a number (e.g.6 divisors->{ 1 2 3 6 })[ length 1 ] keep(e.g.{ 1 2 3 6 } [ length 1 ] keep->4 1 { 1 2 3 6 })n/vdivide number by vector (e.g.1 { 1 2 3 6 } n/v->{ 1 1/2 1/3 1/6 })Σtake the summod 0 =is it a divisor?
Factor + lists.lazy math.primes.factors, 69 bytes
[ 1 lfrom [ divisors [ length 1 ] keep n/v sum / integer? ] lfilter ]
It's a quotation that returns an infinite lazy list of the harmonic divisor numbers.
Explanation
1 lfroman infinite lazy list of natural numbers[ ... ] lfilterselect numbers for which the quotation returnstruedivisorsget the divisors of a number (e.g.6 divisors->{ 1 2 3 6 })[ length 1 ] keep(e.g.{ 1 2 3 6 } [ length 1 ] keep->4 1 { 1 2 3 6 })n/vdivide number by vector (e.g.1 { 1 2 3 6 } n/v->{ 1 1/2 1/3 1/6 })sumtake the sum/divide forming a rational numberinteger?is it an integer?