A066189 Sum of all partitions of n into distinct parts.
0, 1, 2, 6, 8, 15, 24, 35, 48, 72, 100, 132, 180, 234, 308, 405, 512, 646, 828, 1026, 1280, 1596, 1958, 2392, 2928, 3550, 4290, 5184, 6216, 7424, 8880, 10540, 12480, 14784, 17408, 20475, 24048, 28120, 32832, 38298, 44520, 51660, 59892, 69230, 79904
Offset: 0
Examples
The strict integer partitions of 6 are {(6), (5,1), (4,2), (3,2,1)} with sum 6+5+1+4+2+3+2+1 = 24. - _Gus Wiseman_, May 09 2019
Links
- Alois P. Heinz, Table of n, a(n) for n = 0..10000
Crossrefs
Programs
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Maple
b:= proc(n, i) option remember; `if`(n=0, [1, 0], `if`(i>n, [0$2], b(n, i+1)+(p-> p+[0, i*p[1]])(b(n-i, i+1)))) end: a:= n-> b(n, 1)[2]: seq(a(n), n=0..80); # Alois P. Heinz, Sep 01 2014
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Mathematica
PartitionsQ[ Range[ 60 ] ]Range[ 60 ] nmax=60; CoefficientList[Series[x*D[Product[1+x^k, {k, 1, nmax}], x], {x, 0, nmax}], x] (* Vaclav Kotesovec, Nov 21 2016 *)
Formula
G.f.: sum(n>=1, n*q^(n-1)/(1+q^n) ) * prod(n>=1, 1+q^n ). - Joerg Arndt, Aug 03 2011
a(n) = n * A000009(n). - Vaclav Kotesovec, Sep 25 2016
G.f.: x*f'(x), where f(x) = Product_{k>=1} (1 + x^k). - Vaclav Kotesovec, Nov 21 2016