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.

A321508 Expansion of Product_{k>=1} 1/(1 - x^prime(k))^A056768(k).

Original entry on oeis.org

1, 0, 1, 1, 1, 3, 2, 6, 4, 7, 10, 15, 17, 30, 31, 41, 58, 81, 105, 143, 177, 218, 306, 393, 550, 618, 883, 1024, 1395, 1810, 2372, 2985, 3682, 4762, 6077, 7634, 10160, 12517, 15448, 19820, 24754, 32108, 40085, 50851, 62331, 78548, 98505, 125596, 156565
Offset: 0

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Author

Ilya Gutkovskiy, Nov 11 2018

Keywords

Comments

a(n) is the number of partitions of n into prime parts prime(k) of A056768(k) kinds.

Examples

			a(7) = 6 because we have [{7}], [{5, 2}], [{5}, {2}], [{3, 2, 2}], [{3, 2}, {2}] and [{3}, {2}, {2}].
		

Crossrefs

Programs

  • Mathematica
    b[n_] := b[n] = SeriesCoefficient[Product[1/(1 - x^Prime[k]), {k, 1, n}], {x, 0, Prime[n]}]; a[n_] := a[n] = SeriesCoefficient[Product[1/(1 - x^Prime[k])^b[k], {k, 1, n}], {x, 0, n}]; Table[a[n], {n, 0, 48}]

Formula

G.f.: Product_{k>=1} 1/(1 - x^A000040(k))^A000607(A000040(k)).