A209384 - OEIS

%I #14 Mar 30 2012 17:34:43

%S 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,

%T 11,11,12,13,13,13,13,13,13,14,15,16,16,16,16,16,16,17,18,19,20,20,20,

%U 20,20,20,21,22,23,24

%N 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.

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

%H Paolo P. Lava, <a href="/A209384/b209384.txt">Table of n, a(n) for n = 0..10000</a>

%t (* Conway Staircase 7 start up vector*)

%t f[0] = 0; f[1] = 1; f[2] = 1; f[3] = 1; f[4] = 1; f[5] = 1; f[6] = 1;

%t f[n_] := f[n] = f[f[f[n - 1]]] + f[n - f[f[n - 1]]];

%t a = Table[f[n], {n, 0, 200}]

%Y Cf. A004001.

%K nonn

%O 0,8

%A _Roger L. Bagula_, Mar 07 2012