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.

Showing 1-2 of 2 results.

A328853 Dirichlet g.f.: Product_{k>=2} 1 / (1 - k^(-s))^(k - 1).

Original entry on oeis.org

1, 1, 2, 4, 4, 7, 6, 11, 11, 13, 10, 24, 12, 19, 22, 32, 16, 38, 18, 44, 32, 31, 22, 76, 34, 37, 46, 64, 28, 89, 30, 84, 52, 49, 58, 143, 36, 55, 62, 138, 40, 129, 42, 104, 116, 67, 46, 233, 69, 119, 82, 124, 52, 188, 94, 200, 92, 85, 58, 341, 60, 91, 168, 230
Offset: 1

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Author

Ilya Gutkovskiy, Oct 28 2019

Keywords

Comments

Dirichlet convolution of A050367 with A114592.

Crossrefs

Formula

a(n) = Sum_{d|n} A050367(n/d) * A114592(d).

A328876 Dirichlet g.f.: Product_{k>=2} (1 + k^(-s))^(k + 1).

Original entry on oeis.org

1, 3, 4, 8, 6, 19, 8, 25, 16, 29, 12, 66, 14, 39, 40, 69, 18, 95, 20, 102, 54, 59, 24, 220, 41, 69, 72, 138, 30, 237, 32, 191, 82, 89, 84, 379, 38, 99, 96, 342, 42, 321, 44, 210, 206, 119, 48, 679, 78, 240, 124, 246, 54, 459, 128, 464, 138, 149, 60, 971
Offset: 1

Views

Author

Ilya Gutkovskiy, Oct 29 2019

Keywords

Comments

Number of ways to factor n into distinct factors with 3 kinds of 2, 4 kinds of 3, ..., k+1 kinds of k.
Dirichlet convolution of A045778 with A050368.

Crossrefs

Programs

  • PARI
    seq(n)={my(v=vector(n, k, k==1)); for(k=2, n, my(m=logint(n, k), p=(1 + x + O(x*x^m))^(k+1), w=vector(n)); for(i=0, m, w[k^i]=polcoef(p, i)); v=dirmul(v, w)); v} \\ Andrew Howroyd, Oct 29 2019

Formula

a(n) = Sum_{d|n} A045778(n/d) * A050368(d).
Showing 1-2 of 2 results.