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.

A373295 Expansion of 1/Product_{k>=1} (1 - x^k)^(valuation(k,4) + 1).

Original entry on oeis.org

1, 1, 2, 3, 6, 8, 13, 18, 29, 39, 57, 77, 112, 148, 205, 271, 373, 485, 649, 841, 1116, 1431, 1865, 2379, 3080, 3896, 4979, 6268, 7961, 9953, 12524, 15585, 19505, 24135, 29984, 36943, 45678, 56007, 68841, 84080, 102912, 125164, 152449, 184756, 224184, 270691, 327094, 393675
Offset: 0

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Author

Seiichi Manyama, May 31 2024

Keywords

Crossrefs

Programs

  • PARI
    my(N=50, x='x+O('x^N)); Vec(1/prod(k=1, N, (1-x^k)^(valuation(k, 4)+1)))

Formula

G.f.: A(x) = 1/Product_{i>=1, j>=0} (1 - x^(i * 4^j)).
Let A(x) be the g.f. of this sequence, and P(x) be the g.f. of A000041, then P(x) = A(x)/A(x^4).