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.

A339218 Number of partitions of n into prime parts where every part appears at least 2 times.

Original entry on oeis.org

1, 0, 0, 0, 1, 0, 2, 0, 1, 1, 3, 0, 3, 1, 4, 3, 5, 1, 6, 4, 8, 6, 9, 5, 12, 9, 14, 11, 17, 13, 22, 17, 24, 21, 31, 26, 37, 31, 42, 39, 52, 46, 61, 56, 71, 67, 84, 79, 100, 95, 114, 111, 135, 131, 158, 154, 180, 180, 212, 209, 244, 244, 280, 283, 324, 325, 372, 378, 426, 434, 487
Offset: 0

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Author

Ilya Gutkovskiy, Nov 27 2020

Keywords

Examples

			a(10) = 3 because we have [5, 5], [3, 3, 2, 2] and [2, 2, 2, 2, 2].
		

Crossrefs

Programs

  • Mathematica
    nmax = 70; CoefficientList[Series[Product[1 + x^(2 Prime[k])/(1 - x^Prime[k]), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

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