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.

A254438 Natural numbers k such that k is a multiple of its number of "feasible" partitions.

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 10, 11, 12, 13, 28, 30, 33, 36, 38, 39, 40, 72, 92, 110, 114, 116, 118, 119, 120, 121, 330, 350, 355, 357, 360, 362, 363, 364, 1086, 1088, 1090, 1091, 1092, 1093, 3248, 3270, 3273, 3276, 3278, 3279, 3280, 9792, 9828, 9830, 9834, 9836, 9838, 9839, 9840, 9841, 29376, 29512, 29515, 29517, 29520, 29522, 29523, 29524
Offset: 1

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Author

Md. Towhidul Islam, Mar 01 2015

Keywords

Comments

This sequence lists the natural numbers k that are divisible by A254296(k).

Examples

			For n=1,2,3, A254296(n)=1, so they are in the sequence.
For n=4,6,8,10, A254296(n)=2, so they are in the sequence.
For n=5,9, A254296(n)=2, so they are not in the sequence.
		

Crossrefs

Programs

  • Mathematica
    (* This program is not suitable to compute a large number of terms. *)
    okQ[v_] := Module[{s=0}, For[i=1, i <= Length[v], i++, If[v[[i]] > 2s+1, Return[False], s += v[[i]]]]; Return[True]];
    b[n_] := b[n] = With[{k = Ceiling[Log[3, 2 n]]}, Select[Reverse /@ IntegerPartitions[n, {k}], okQ] // Length];
    Reap[Do[If[Divisible[k, b[k]], Print[k]; Sow[k]], {k, 1, 120}]][[2, 1]] (* Jean-François Alcover, Nov 03 2018 *)

Extensions

a(48)-a(64) added by Md. Towhidul Islam, Apr 18 2015