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.

A360379 a(n) = number of the antidiagonal of the Wythoff array (A035513) that includes prime(n).

Original entry on oeis.org

2, 3, 4, 3, 4, 6, 7, 8, 7, 6, 9, 8, 11, 17, 7, 21, 23, 24, 26, 13, 10, 14, 21, 10, 10, 39, 40, 13, 27, 19, 49, 12, 53, 23, 17, 37, 11, 63, 41, 14, 69, 29, 12, 47, 76, 10, 81, 35, 55, 88, 12, 92, 18, 26, 40, 101, 65, 104, 67, 108, 44, 30, 118, 75, 120, 22
Offset: 1

Views

Author

Clark Kimberling, Feb 05 2023

Keywords

Comments

Conjecture: Only a finite number of positive integers are missing.

Examples

			The first 6 antidiagonals of the Wythoff array are (1), (2,4), (3,7,6), (5,11,10,9), (8,18,16,15,12), (12,29,26,24,20,14). The 10th prime is 29, which occurs in antidiagonal 6, so a(10) = 6.
		

Crossrefs

Programs

  • Mathematica
    W[n_, k_] := Fibonacci[k + 1] Floor[n*GoldenRatio] + (n - 1) Fibonacci[k];
    t = Table[W[n - k + 1, k], {n, 300}, {k, n, 1, -1}];
    Map[#[[1]] &, Most[Reap[NestWhileList[# + 1 &, 1,
    Length[Sow[FirstPosition[t, Prime[#]]]] > 1 &]][[2]][[1]]]]
    (* Peter J. C. Moses, Feb 08 2023 *)