Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #13 May 21 2022 14:54:01
%S 4,7,18,80,242,728,2186,6560,19682,59048,177146,531440
%N Smallest b > 1 such that there exists an odd prime p with p < b such that b^(p-1) == 1 (mod p^n).
%C Conjecture: For n > 3, a(n) = A024023(n) = A103453(n).
%o (PARI) a(n) = my(b=2); while(1, forprime(p=3, b-1, if(Mod(b, p^n)^(p-1)==1, return(b))); b++)
%K nonn,more
%O 1,1
%A _Felix Fröhlich_, Jan 15 2016
%E a(11) from _Michael S. Branicky_, May 19 2022
%E a(12) from _Michael S. Branicky_, May 21 2022