%I #21 Aug 28 2021 02:50:41
%S 1,13,169,1027,2197,13351,28561,81133,173563,371293,468481,685633,
%T 1054729,2256319,2890927,4826809,6090253,6409507,8913229,13711477,
%U 29332147,37009999,37582051,54165007,62748517,79173289,83323591,115871977,178249201,228383233
%N Positive integers k such that k | (12^k + 1).
%Y Solutions to b^k == -1 (mod k): A006521 (b=2), A015949 (b=3), A015950 (b=4), A015951 (b=5), A015953 (b=6), A015954 (b=7), A015955 (b=8), A015957 (b=9), A015958 (b=10), A015960 (b=11), this sequence (b=12), A015963 (b=13), A015965 (b=14), A015968 (b=15), A015969 (b=16).
%Y Column k=12 of A333429.
%K nonn
%O 1,2
%A _Robert G. Wilson v_
%E More terms from _Max Alekseyev_, Aug 01 2011
%E a(30) from _Jon E. Schoenfield_, Aug 27 2021