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.

A191361 Number of the diagonal of the Wythoff difference array that contains n.

Original entry on oeis.org

0, 1, -1, -2, 2, -3, 0, -4, -5, -1, -6, -7, 3, -8, -2, -9, -10, 1, -11, -3, -12, -13, -4, -14, -15, 0, -16, -5, -17, -18, -6, -19, -20, 4, -21, -7, -22, -23, -1, -24, -8, -25, -26, -9, -27, -28, 2, -29, -10, -30, -31, -2, -32, -11, -33, -34, -12, -35, -36, -3
Offset: 1

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Author

Clark Kimberling, May 31 2011

Keywords

Comments

Every integer occurs in A191361 (infinitely many times).
Represent the array as {g(i,j): i>=1, j>=1}. Then for m>=0, (diagonal #m) is the sequence (g(i,i+m)), i>=1;
for m<0, (diagonal #m) is the sequence (g(i+m,i)), i>=1.

Examples

			Diagonal #0 (the main diagonal) of A080164 is (1,7,26,...), so a(1)=0, a(7)=0, a(26)=0.
		

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio; f[n_] := Fibonacci[n];
    g[i_, j_] := f[2 j - 1]*Floor[i*r] + (i - 1) f[2 j - 2];
    TableForm[Table[g[i, j], {i, 1, 10}, {j, 1, 5}]]
    (* A080164, Wythoff difference array *)
    a = Flatten[Table[If[g[i, j] == n, j - i, {}], {n, 60}, {i, 50}, {j, 50}]]
    (* a=A191361 *)