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.

A248188 Numbers k such that A248186(k+1) = A248186(k) + 1.

Original entry on oeis.org

4, 5, 7, 8, 10, 11, 12, 14, 15, 17, 18, 20, 21, 23, 24, 25, 27, 28, 30, 31, 33, 34, 36, 37, 38, 40, 41, 43, 44, 46, 47, 49, 50, 51, 53, 54, 56, 57, 59, 60, 62, 63, 64, 66, 67, 69, 70, 72, 73, 74, 76, 77, 79, 80, 82, 83, 85, 86, 87, 89, 90, 92, 93, 95, 96, 98
Offset: 1

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Author

Clark Kimberling, Oct 04 2014

Keywords

Comments

a(n) = A059539(n+2) = [3^(1/3)*(n+2)] for n = 1..655, but a(656) = 948 = A059539(658)-1.

Examples

			The difference sequence of A248186 is (0, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, ...), so that A248187 = (1, 2, 3, 6, 9, 13, 16, 19, 22,...) and A248188 = (4, 5, 7, 8, 10, 11, 12, 14, 15, 17,...), the complement of A248186.
		

Crossrefs

Programs

  • Mathematica
    $MaxExtraPrecision = Infinity;
    z = 800; p[k_] := p[k] = Sum[1/(h*(h + 1)*(h + 2)*(h + 3)), {h, 1, k}];
    N[Table[1/18 - p[n], {n, 1, z/10}]]
    f[n_] := f[n] = Select[Range[z], 1/18 - p[#] < 1/n^3 &, 1]
    u = Flatten[Table[f[n], {n, 1, z}]]   (* A248186 *)
    Flatten[Position[Differences[u], 0]]  (* A248187 *)
    Flatten[Position[Differences[u], 1]]  (* A248188 *)