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.

A317359 a(0) = 0, a(1) = 1; for n >= 2, a(n) = freq(a(n-g(n)),n) where g = A000523 and freq(i, j) is the number of times i appears in the terms a(0) .. a(j-1).

Original entry on oeis.org

0, 1, 1, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 3, 3, 3, 3, 8, 8, 8, 8, 4, 4, 4, 4, 7, 7, 7, 7, 4, 4, 4, 4, 4, 12, 12, 12, 12, 12, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 5, 5, 5, 5, 5, 11, 11, 11, 11, 11, 5, 5, 5, 5, 5, 5, 17, 17, 17, 17, 17, 17, 6, 6, 6, 6, 6, 6, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 11, 11, 11, 11, 11
Offset: 0

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Author

Altug Alkan, Jul 26 2018

Keywords

Crossrefs

Programs

  • Maple
    b:= proc() 0 end:
    a:= proc(n) option remember; local t;
          t:= `if`(n<2, n, b(a(n-ilog2(n))));
          b(t):= b(t)+1; t
        end:
    seq(a(n), n=0..200);  # Alois P. Heinz, Jul 26 2018
  • Mathematica
    c = <||>; f[n_] := If[KeyExistsQ[c, n], c[n], 0]; a[n_] := a[n] = Block[{v}, v = If[n < 2, n, f[a[n - Floor@ Log2@ n]]]; If[f[v] > 0, c[v] = c[v] + 1, c[v] = 1]; v]; Array[a, 96, 0] (* Giovanni Resta, Jul 26 2018 *)