%I #17 Oct 12 2024 09:02:14
%S 1,121487,293957,13449179,549999887
%N Numbers k such that A007908(k) == 1 (mod k).
%C a(6) > 10^11. - _Jason Yuen_, Oct 12 2024
%o (Python) # See A029455 for concat_mod
%o def isok(k): return concat_mod(10, k, k)==1%k # _Jason Yuen_, Oct 12 2024
%Y Cf. A007908, A029455, A029479, A110740.
%K nonn,base,hard,more
%O 1,2
%A _Max Alekseyev_, Jun 06 2023