A166493 A Per Bak sand pile collapse sequence using Hofstadter Q:A005185, of the A153112 form.

1, 1, 1, 2, 3, 3, 4, 5, 5, 6, 6, 6, 8, 8, 8, 10, 9, 10, 1, 7, 15, 12, 11, 14, 14, 12, 16, 16, 16, 16, 16, 20, 17, 17, 20, 11, 21, 25, 18, 20, 26, 22, 24, 19, 27, 17, 23, 30, 13, 28, 36, 24, 25, 32, 27, 30, 32, 28, 32, 36, 30, 32, 3, 50, 40, 22, 43, 31, 37, 35, 28, 40, 44, 33, 38, 49

Offset

0,4

Links

Table of n, a(n) for n=0..75.

Mathematica

f[0] = 1; f[1] = 1; f[2] = 1;
f[n_] := f[n] = If[Mod[Floor[Sum[f[i], {i, 0, n - 1}]/2], 2^(4 + Mod[n, 3])] == 0, 1 + Mod[n, 3], f[n - f[n - 1]] + f[n - f[n - 2]]];
a = Table[f[n], {n, 0, 200}]

Crossrefs

Cf. A153112, A005185.

Sequence in context: A296020 A266350 A123579 * A005185 A119466 A100922

Adjacent sequences: A166490 A166491 A166492 * A166494 A166495 A166496

Keyword

nonn,uned

Author

Roger L. Bagula, Oct 15 2009

Status

approved