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.

A193848 Triangular array: (1/2)*A193846.

Original entry on oeis.org

1, 2, 4, 4, 14, 13, 8, 40, 68, 40, 16, 104, 256, 284, 121, 32, 256, 824, 1336, 1094, 364, 64, 608, 2416, 5144, 6196, 4010, 1093, 128, 1408, 6656, 17536, 27824, 26608, 14216, 3280, 256, 3200, 17536, 55040, 108256, 136688, 108256, 49208, 9841, 512
Offset: 0

Views

Author

Clark Kimberling, Aug 07 2011

Keywords

Examples

			Triangle begins:
    1;
    2,    4;
    4,   14,   13;
    8,   40,   68,    40;
   16,  104,  256,   284,   121;
   32,  256,  824,  1336,  1094,   364;
   64,  608, 2416,  5144,  6196,  4010,  1093;
  128, 1408, 6656, 17536, 27824, 26608, 14216, 3280;
  ...
		

Crossrefs

Cf. A193846.

Programs

  • Mathematica
    (See A193846.)
  • PARI
    T(n)={[Vecrev(p) | p<-Vec(1/(1 - 2*(1 + 2*y)*x + y*(2 + 3*y)*x^2) + O(x*x^n))]}
    { my(A=T(10)); for(i=1, #A, print(A[i])) } \\ Andrew Howroyd, Feb 18 2024

Formula

G.f.: 1/(1 - 2*(1 + 2*y)*x + y*(2 + 3*y)*x^2). - Andrew Howroyd, Feb 18 2024