%I #16 Mar 18 2024 16:05:48
%S 1,3,14,11,6,1941491,10,83,31,13,123,35,71,27,34913,241,18,8059,34,
%T 349,44,25,39,100867561,76,231,253,66203,57,227,139,45,184,37,111,97,
%U 55,41,103,1099,81,66791,53
%N Least k such that 2^(2^k) = n (mod k).
%C First occurrence of n in sequence A155836.
%C a(43) > 12500000. - _Tyler Busby_, Mar 15 2024
%Y Cf. A015910 (2^n mod n), A036236, A155836.
%K nonn,more
%O 0,2
%A _T. D. Noe_, Jan 29 2009