cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A282207 Expansion of Product_{k>=0} (1 + (2*k + 1)*x^(2*k+1)).

Original entry on oeis.org

1, 1, 0, 3, 3, 5, 5, 7, 22, 24, 30, 32, 73, 75, 91, 198, 277, 309, 339, 560, 689, 1078, 1126, 1567, 2703, 3396, 3676, 5086, 7046, 8241, 10896, 13072, 19891, 22975, 27922, 41597, 56117, 62459, 77183, 100793, 131846, 161665, 191446, 255225, 311247, 408418, 467460, 599970, 843441
Offset: 0

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Author

Ilya Gutkovskiy, Feb 09 2017

Keywords

Comments

Sum of products of terms in all partitions of n into distinct odd parts.

Examples

			a(10) = 30 because we have [9, 1], [7, 3], 9*1 = 9, 7*3 = 21 and 9 + 21 = 30.
		

Crossrefs

Programs

  • Mathematica
    nmax = 48; CoefficientList[Series[Product[1 + (2 k + 1) x^(2 k + 1), {k, 0, nmax}], {x, 0, nmax}], x]

Formula

G.f.: Product_{k>=0} (1 + (2*k + 1)*x^(2*k+1)).