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.

A248638 Numbers k such that A248636(k+1) = A248636(k) + 1.

Original entry on oeis.org

1, 3, 5, 6, 9, 11, 13, 16, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 49, 52, 55, 58, 62, 65, 68, 72, 75, 79, 82, 85, 89, 92, 96, 99, 103, 106, 110, 113, 117, 120, 124, 127, 131, 135, 138, 142, 145, 149, 152, 156, 160, 163, 167, 170, 174, 178, 181, 185, 189
Offset: 1

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Author

Clark Kimberling, Oct 11 2014

Keywords

Examples

			(A248636(k+1) = A248636(k)) = (2, 1, 2, 1, 2, 2, 1, 1, 2, 1, 2, 1, 2, 1, 1, 2,... ), so that A248637 = (2, 4, 7, 8, 10, 12, 14, ... ) and A248638 = (1, 3, 5, 6, 9, 11, 13, ...).
		

Crossrefs

Programs

  • Mathematica
    z = 300; p[k_] := p[k] = Sum[(h^3/3^h), {h, 1, k}];
    d = N[Table[33/8 - p[k], {k, 1, z/5}], 12]
    f[n_] := f[n] = Select[Range[z], 33/8 - p[#] < 1/4^n &, 1];
    u = Flatten[Table[f[n], {n, 1, z}]]  (* A248636 *)
    d = Differences[u]
    v = Flatten[Position[d, 1]] (* A248637 *)
    w = Flatten[Position[d, 2]] (* A248638 *)