A186188 Least k such that A156077^(k)(n)=1 where a^(k)=a(a^(k-1)).

1, 1, 1, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 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, 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

Offset: 1

Author

Benoit Cloitre, Feb 14 2011

Keywords

• nonn

References

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

Crossrefs

Cf. A000002, A156077.

Programs

PARI

a(n)=if(n<0,0,t=n;c=1;while(A156077(t)>1,t=A156077(t);c++);c)

Formula

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