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.

A202451 Upper triangular Fibonacci matrix, by SW antidiagonals.

Original entry on oeis.org

1, 0, 1, 0, 1, 2, 0, 0, 1, 3, 0, 0, 1, 2, 5, 0, 0, 0, 1, 3, 8, 0, 0, 0, 1, 2, 5, 13, 0, 0, 0, 0, 1, 3, 8, 21, 0, 0, 0, 0, 1, 2, 5, 13, 34, 0, 0, 0, 0, 0, 1, 3, 8, 21, 55, 0, 0, 0, 0, 0, 1, 2, 5, 13, 34, 89, 0, 0, 0, 0, 0, 0, 1, 3, 8, 21, 55, 144
Offset: 1

Views

Author

Clark Kimberling, Dec 19 2011

Keywords

Examples

			Northwest corner:
1...1...2...3...5...8...13...21...34
0...1...1...2...3...5....8...13...21
0...0...1...1...2...3....5....8...13
0...0...0...1...1...2....3....5....8
		

Crossrefs

Programs

  • Mathematica
    n = 12;
    Q = NestList[Most[Prepend[#, 0]] &, #, Length[#] - 1] &[Table[Fibonacci[k], {k, 1, n}]];
    P = Transpose[Q]; F = P.Q;
    Flatten[Table[P[[i]][[k + 1 - i]], {k, 1, n}, {i, 1, k}]] (* A202451 as a sequence *)
    Flatten[Table[Q[[i]][[k + 1 - i]], {k, 1, n}, {i, 1, k}]] (* A202452 as a sequence *)
    Flatten[Table[F[[i]][[k + 1 - i]], {k, 1, n}, {i, 1, k}]] (* A202453 as a sequence *)
    TableForm[Q]  (* A202451, upper triangular Fibonacci matrix *)
    TableForm[P]  (* A202452, lower triangular Fibonacci matrix *)
    TableForm[F]  (* A202453, Fibonacci self-fusion matrix *)
    TableForm[FactorInteger[F]]

Formula

Row n consists of n-1 zeros followed by the Fibonacci sequence (1, 1, 2, 3, 5, 8, ...).