A331927 Number of compositions (ordered partitions) of n into distinct divisors of n.
1, 1, 1, 1, 1, 1, 7, 1, 1, 1, 1, 1, 31, 1, 1, 1, 1, 1, 31, 1, 25, 1, 1, 1, 895, 1, 1, 1, 121, 1, 151, 1, 1, 1, 1, 1, 1135, 1, 1, 1, 865, 1, 31, 1, 1, 1, 1, 1, 11935, 1, 1, 1, 1, 1, 151, 1, 841, 1, 1, 1, 129439, 1, 1, 1, 1, 1, 127, 1, 1, 1, 1
Offset: 0
Keywords
Examples
a(6) = 7 because we have [6], [3, 2, 1], [3, 1, 2], [2, 3, 1], [2, 1, 3], [1, 3, 2] and [1, 2, 3].
Programs
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PARI
a(n)={if(n==0, 1, my(v=divisors(n)); subst(serlaplace(polcoef(prod(i=1, #v, 1 + y*x^v[i] + O(x*x^n)), n)), y, 1))} \\ Andrew Howroyd, Feb 01 2020
Formula
a(n) = A331928(n) + 1 for n > 0.