

A097986


Number of partitions of n into distinct parts, each of which has a part which divides every part in the partition.


2



1, 1, 2, 2, 2, 4, 3, 5, 5, 7, 6, 12, 9, 13, 15, 20, 18, 28, 26, 37, 39, 47, 49, 71, 68, 85, 94, 117, 120, 159, 160, 201, 216, 257, 277, 348, 357, 430, 470, 562, 592, 720, 758, 901, 981, 1134, 1220, 1457, 1542, 1798, 1952, 2250, 2419, 2819, 3023, 3482, 3773, 4291
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OFFSET

1,3


LINKS

Table of n, a(n) for n=1..58.


FORMULA

a(n) = Sum_{dn} A025147(d1). G.f.: Sum(x^k*Product(1+x^(k*i), i=2..infinity), k=1..infinity).


MATHEMATICA

Take[ CoefficientList[ Expand[ Sum[x^k*Product[1 + x^(k*i), {i, 2, 62}], {k, 62}]], x], {2, 60}] (from Robert G. Wilson v Nov 01 2004)


CROSSREFS

Cf. A083710.
Sequence in context: A234615 A029145 A238999 * A210596 A240078 A228660
Adjacent sequences: A097983 A097984 A097985 * A097987 A097988 A097989


KEYWORD

easy,nonn


AUTHOR

Vladeta Jovovic, Oct 23 2004


EXTENSIONS

More terms from Robert G. Wilson v, Nov 01 2004


STATUS

approved



