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.

A118409 Unsigned row sums of triangle A118407.

Original entry on oeis.org

1, 1, 3, 5, 5, 7, 11, 17, 21, 27, 47, 73, 85, 111, 187, 289, 341, 443, 751, 1161, 1365, 1775, 3003, 4641, 5461, 7099, 12015, 18569, 21845, 28399, 48059, 74273, 87381, 113595, 192239, 297097, 349525, 454383, 768955, 1188385, 1398101, 1817531
Offset: 0

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Author

Paul D. Hanna, Apr 27 2006

Keywords

Crossrefs

Cf. A118407 (triangle), A118408 (row sums).

Programs

  • PARI
    {a(n)=polcoeff((1+2*x^2+2*x^3-3*x^4+2*x^5-2*x^6)/(1+x^4)/(1-4*x^4)/(1-x+x*O(x^n)),n)}

Formula

G.f.: (1+2*x^2+2*x^3-3*x^4+2*x^5-2*x^6)/(1+x^4)/(1-4*x^4)/(1-x).