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.

A131049 (1/4) * (A007318^3 - A007318^(-1)).

Original entry on oeis.org

1, 2, 2, 7, 6, 3, 20, 28, 12, 4, 61, 100, 70, 20, 5, 182, 366, 300, 140, 30, 6, 547, 1274, 1281, 700, 245, 42, 7, 1640, 4376, 5096, 3416, 1400, 392, 56, 8, 4921, 14760, 19692, 15288, 7686, 2520, 588, 72, 9
Offset: 1

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Author

Gary W. Adamson, Jun 12 2007

Keywords

Comments

Row sums = powers of 4: (1, 4, 16, 64, ...).
Left border = A015518: (1, 2, 7, 20, 61, 182, ...).

Examples

			First few rows of the triangle:
    1;
    2,    2;
    7,    6,    3;
   20,   28,   12,   4;
   61,  100,   70,  20,   5;
  182,  366,  300, 140,  30,  6;
  547, 1274, 1281, 700, 245, 42, 7;
  ...
		

Crossrefs

Formula

(1/4) * (P^3 - 1/P), where P = Pascal's triangle, A007318. Delete right border of zeros.