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.

A214970 Integers n that divide f(n), where f is the change-of-base function defined at A214969, using b = (golden ratio) and c=b^2.

Original entry on oeis.org

1, 4, 8, 11, 19, 22, 29, 48, 55, 58, 76, 124, 152, 192, 199, 323, 341, 348, 377, 398, 496, 521, 844, 912, 969, 992, 1042, 1292, 1364, 2208, 2255, 2356, 2388, 2584, 2728, 3072, 3376, 3553, 3571, 5779, 5952, 6119, 6169, 6252, 6752, 6820, 7142
Offset: 1

Views

Author

Clark Kimberling, Oct 17 2012

Keywords

Comments

Conjecture: L(2k-1) and L(2k)+1 are terms of the sequence, for all positive integers k, where L=A000032 (Lucas numbers).

Examples

			8 = r^4 + 1/r^4, where r = (1 + sqrt(5))/2 (the golden ratio), so f(8) = r^8 + 1/r^8 = 48, so 8 divides f(8).
		

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio; f[x_] := Floor[Log[r, x]]; t[n_] := RealDigits[n, r, 1000]; p[n_] := Flatten[Position[t[n][[1]], 1]]; m[n_] := If[MemberQ[f[n] + 1 - p[n], 0], 1, 0]; t = Table[m[n], {n, 1, 900}]; Flatten[Position[t,1]]