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.

A281905 Expansion of Sum_{i>=2} prime(i)*x^prime(i)/(1 - x^prime(i)) / Product_{j>=1} (1 - x^j).

Original entry on oeis.org

0, 0, 3, 3, 11, 17, 35, 49, 84, 124, 199, 280, 426, 594, 858, 1172, 1654, 2224, 3061, 4066, 5472, 7196, 9543, 12391, 16196, 20857, 26921, 34351, 43924, 55574, 70419, 88455, 111142, 138697, 173025, 214527, 265895, 327831, 403825, 495234, 606755, 740371, 902507, 1096215, 1329912, 1608445, 1942926, 2340203
Offset: 1

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Author

Ilya Gutkovskiy, Feb 01 2017

Keywords

Comments

Total sum of odd prime parts in all partitions of n.
Convolution of the sequences A000041 and A005069.

Examples

			a(5) = 11 because we have [5], [4, 1], [3, 2], [3, 1, 1], [2, 2, 1], [2, 1, 1, 1], [1, 1, 1, 1, 1] and 5 + 3 + 3 = 11.
		

Crossrefs

Programs

  • Mathematica
    nmax = 48; Rest[CoefficientList[Series[Sum[Prime[i] x^Prime[i]/(1 - x^Prime[i]), {i, 2, nmax}]/Product[1 - x^j, {j, 1, nmax}], {x, 0, nmax}], x]]

Formula

G.f.: Sum_{i>=2} prime(i)*x^prime(i)/(1 - x^prime(i)) / Product_{j>=1} (1 - x^j).