1,2

If n is a power of 2 a(n)=n. Conjecture : if n>47 a(n) < prime(n)

Harvey P. Dale, Table of n, a(n) for n = 1..1000

dvkn[n_]:=Module[{k=1}, While[!Divisible[2^k-k, n], k++]; k]; Array[dvkn, 80] (* Harvey P. Dale, Dec 23 2011 *)

See A135359 for another version.

Sequence in context: A193358 A214028 A079533 * A135359 A098217 A151846

Adjacent sequences: A072869 A072870 A072871 * A072873 A072874 A072875

easy,nonn

Benoit Cloitre, Jul 28 2002

Edited by N. J. A. Sloane, May 27 2010

approved