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.

A294606 Expansion of Product_{k>=1} (1 - k*x^k)^(k^k).

Original entry on oeis.org

1, -1, -8, -73, -919, -13977, -253640, -5290184, -124681406, -3272865905, -94671665085, -2991846831531, -102566663464544, -3791541404744714, -150357943095635464, -6367699625807475503, -286854179220742344135, -13697182490105378305606
Offset: 0

Views

Author

Seiichi Manyama, Nov 04 2017

Keywords

Crossrefs

Column k=1 of A294605.
Cf. A294608.

Programs

  • Mathematica
    nmax = 20; CoefficientList[Series[Product[(1 - k*x^k)^(k^k), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Nov 05 2017 *)
  • PARI
    N=66; x='x+O('x^N); Vec(prod(k=1, N, (1-k*x^k)^k^k))

Formula

a(0) = 1 and a(n) = -(1/n) * Sum_{k=1..n} A294608(k) * a(n-k) for n > 0.

A294610 Expansion of Product_{k>=1} 1/(1 - k*x^k)^(k^k).

Original entry on oeis.org

1, 1, 9, 90, 1154, 17427, 309117, 6285102, 144603015, 3717580810, 105696353842, 3293810230381, 111651093529948, 4089889271054734, 160989247361249558, 6776381334102511286, 303712681809603918633, 14439887378431671417669
Offset: 0

Views

Author

Seiichi Manyama, Nov 04 2017

Keywords

Crossrefs

Column k=1 of A294609.

Programs

  • Mathematica
    nmax = 20; CoefficientList[Series[Product[1/(1 - k*x^k)^(k^k), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Nov 05 2017 *)
  • PARI
    N=66; x='x+O('x^N); Vec(1/prod(k=1, N, (1-k*x^k)^k^k))

Formula

a(0) = 1 and a(n) = (1/n) * Sum_{k=1..n} A294608(k) * a(n-k) for n > 0.
Showing 1-2 of 2 results.