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.

A094570 Triangle T(n,k) read by rows: T(n,k) = F(k) + F(n-k) where F(n) is the n-th Fibonacci number.

Original entry on oeis.org

0, 1, 1, 1, 2, 1, 2, 2, 2, 2, 3, 3, 2, 3, 3, 5, 4, 3, 3, 4, 5, 8, 6, 4, 4, 4, 6, 8, 13, 9, 6, 5, 5, 6, 9, 13, 21, 14, 9, 7, 6, 7, 9, 14, 21, 34, 22, 14, 10, 8, 8, 10, 14, 22, 34, 55, 35, 22, 15, 11, 10, 11, 15, 22, 35, 55, 89, 56, 35, 23, 16, 13, 13, 16, 23, 35, 56, 89, 144, 90, 56, 36, 24, 18, 16, 18, 24, 36, 56, 90, 144
Offset: 0

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Author

Clark Kimberling, May 12 2004

Keywords

Examples

			Triangle begins:
0;
1, 1;
1, 2, 1;
2, 2, 2, 2;
3, 3, 2, 3, 3;
5, 4, 3, 3, 4, 5;
8, 6, 4, 4, 4, 6, 8;
13, 9, 6, 5, 5, 6, 9, 13;
21, 14, 9, 7, 6, 7, 9, 14, 21;
		

Crossrefs

Programs

  • PARI
    row(n) = vector(n+1, k, k--; fibonacci(k)+fibonacci(n-k)); \\ Michel Marcus, Mar 22 2021

Formula

Row n: F(0)+F(n), F(1)+F(n-1), F(2)+F(n-2), ..., F(n-1)+F(1), F(n)+F(0).
From Reinhard Zumkeller, Mar 21 2011: (Start)
T(n,0) = T(n,n) = A000045(n).
T(2*n,n) = A006355(n+1).
T(n,k) = A141169(n,k) + A141169(n,n-k). (End)
Sum(T(n,k), 0<=k<=n) = 2*A000071(n+2) = 2*A000045(n+2) - 2. - Philippe Deléham, Apr 07 2013