1,1

Also indices k such that A002380(k) < A002380(k-1).

Table of n, a(n) for n=1..59.

1 == 3^4 (mod 2^4) which is less than 3 == 3^3 (mod 2^3) so 4 is a term.

pm = 0; lst = {}; Do[pn = PowerMod[3, n, 2^n]; If[pn < pm, AppendTo[lst, n]]; pm = pn, {n, 221}]; lst

Cf. A002380.

Sequence in context: A340600 A013625 A182929 * A216552 A034736 A236564

Adjacent sequences: A124399 A124400 A124401 * A124403 A124404 A124405

nonn

Robert G. Wilson v, Dec 14 2006

approved