A209384 Tri-recursive sequence: a(n) = a(a(a(n - 1))) + a(n - a(a(n - 1))), a(0) = 0, a(1) = a(2) = a(3) = a(4) = a(5) = a(6) = 1.

0, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 7, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 12, 13, 13, 13, 13, 13, 13, 14, 15, 16, 16, 16, 16, 16, 16, 17, 18, 19, 20, 20, 20, 20, 20, 20, 21, 22, 23, 24

Offset

0,8

Comments

The staircase effect only shows up with a long start up vector.The staircase disappears at lower start up vector numbers.

Links

Paolo P. Lava, Table of n, a(n) for n = 0..10000

Mathematica

(* Conway Staircase 7 start up vector*)
f[0] = 0; f[1] = 1; f[2] = 1; f[3] = 1; f[4] = 1; f[5] = 1; f[6] = 1;
f[n_] := f[n] = f[f[f[n - 1]]] + f[n - f[f[n - 1]]];
a = Table[f[n], {n, 0, 200}]

Crossrefs

Cf. A004001.

Sequence in context: A102672 A287643 A114955 * A060207 A195932 A327707

Adjacent sequences: A209381 A209382 A209383 * A209385 A209386 A209387

Keyword

nonn

Author

Roger L. Bagula, Mar 07 2012

Status

approved