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.

A143061 Triangle read by rows, A000012 * A127647 * A000012.

Original entry on oeis.org

1, 1, 2, 2, 3, 4, 3, 5, 6, 7, 5, 8, 10, 11, 12, 8, 13, 16, 18, 19, 20, 13, 21, 26, 29, 31, 32, 33, 21, 34, 42, 47, 50, 52, 53, 54, 34, 55, 68, 76, 81, 84, 86, 87, 88, 55, 89, 110, 123, 131, 136, 139, 141, 142, 143, 89, 144, 178, 199, 212, 220, 225, 228, 230, 231
Offset: 1

Views

Author

Gary W. Adamson, Jul 20 2008

Keywords

Comments

Row sums = A014286 (1, 3, 9, 21, 46, 94, ...); left border = Fibonacci numbers.

Examples

			First few rows of the triangle are:
  1;
  1,  2;
  2,  3,  4;
  3,  5,  6,  7;
  5,  8, 10, 11, 12;
  8, 13, 16, 18, 19, 20;
  ...
		

Crossrefs

Programs

  • Maple
    seq(seq(combinat:-fibonacci(i+2)-combinat:-fibonacci(i+2-j),j=1..i),i=1..20); # Robert Israel, Nov 06 2016

Formula

From Robert Israel, Nov 06 2016: (Start)
T(n,k) = A000045(n+2) - A000045(n+2-k) for 1 <= k <= n.
G.f. as triangle: x*y*(1+x^2*y)/((1-x*y)*(1-x-x^2)*(1-x*y-x^2*y^2)). (End)

Extensions

Corrected by Dintle N Kagiso, Nov 06 2016