A186189 least k such that A074286^(k)(n)=1 where a^(k)=a(a^(k-1)).

1, 1, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7

Offset

1,3

References

B. Cloitre, Experimental evidence for the Keane's conjecture, preprint 2011

Links

Table of n, a(n) for n=1..86.

Formula

conjecture: a(n)=floor(log(n)/log(2))+0 or +1

Prog

a(n)=if(n<0, 0, t=n; c=1; while(A074286(t)>1, t=A074286(t); c++); c)

Crossrefs

Sequence in context: A130239 A091092 A218461 * A083375 A088519 A135034

Adjacent sequences: A186186 A186187 A186188 * A186190 A186191 A186192

Keyword

nonn

Author

Benoit Cloitre, Feb 14 2011

Status

approved