A208477 Difference between the sum of odd parts and the sum of even parts in all the partitions of n.
0, 1, 0, 5, 0, 11, 6, 25, 12, 50, 40, 96, 80, 173, 170, 320, 316, 545, 590, 930, 1020, 1552, 1760, 2537, 2900, 4066, 4736, 6450, 7540, 10045, 11856, 15482, 18280, 23555, 27920, 35461, 42032, 52805, 62662, 77955, 92380, 113963, 135040, 165295, 195540, 237866
Offset: 0
Keywords
Links
- Alois P. Heinz, Table of n, a(n) for n = 0..1000
Programs
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Maple
b:= proc(n,i) option remember; local g, h; if n=0 then [1, 0] elif i<1 then [0, 0] else g:= b(n, i-1); h:= `if`(i>n, [0, 0], b(n-i, i)); [g[1]+h[1], g[2]+h[2] +h[1]*i*(2*(i mod 2)-1)] fi end: a:= n-> b(n, n)[2]: seq(a(n), n=0..60); # Alois P. Heinz, Mar 10 2012
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Mathematica
Map[Total[Select[#, OddQ]] - Total[Select[#, EvenQ]] &[Flatten[IntegerPartitions[#]]] &, -1 + Range[30]] (* Peter J. C. Moses, Mar 14 2014 *) max = 60; s = Sum[x^(2i) (x^(2i) - 2i (x-1) - 1)/(x + x^(4i) - (x+1) x^(2i) ), {i, 1, Floor[max/2]}]/QPochhammer[x] + O[x]^max; CoefficientList[s, x] (* Jean-François Alcover, Aug 29 2016, after Alois P. Heinz *)
Formula
G.f.: (Sum_{i>0} (2*i-1)*x^(2*i-1)/(1-x^(2*i-1))-2*i*x^(2*i)/(1-x^(2*i))) / Product_{j>0} (1-x^j). - Alois P. Heinz, Mar 10 2012
Extensions
More terms from Alois P. Heinz, Mar 10 2012