A100932 Number of partitions of n such that multiplicities of parts are divisors of n.

1, 2, 3, 5, 4, 10, 6, 17, 14, 26, 13, 66, 19, 63, 60, 126, 39, 243, 55, 338, 179, 310, 105, 1154, 209, 637, 482, 1458, 257, 3329, 341, 2878, 1200, 2386, 1178, 11262, 761, 4400, 2834, 14512, 1261, 23052, 1611, 18255, 10551, 13858, 2591, 83810, 4678, 38243

Offset

1,2

Links

Table of n, a(n) for n=1..50.

Martin Klazar, What is an answer? — remarks, results and problems on PIO formulas in combinatorial enumeration, part I, arXiv:1808.08449 [math.CO], 2018.

Formula

Coefficient of x^n in expansion of Product_{k=1..n} (1+Sum_{d|n} x^(d*k)).

Maple

with(numtheory): seq(coeff(mul(1+add(x^(d*k), d=divisors(n)), k=1..n), x, n), n=1..60); # C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 19 2005

Crossrefs

Cf. A018818.

Sequence in context: A373998 A247225 A374916 * A064360 A075158 A215526

Adjacent sequences: A100929 A100930 A100931 * A100933 A100934 A100935

Keyword

easy,nonn

Author

Vladeta Jovovic, Jan 11 2005

Extensions

More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 19 2005

Status

approved