This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A364186 #10 Jul 27 2023 12:21:34 %S A364186 31,43,109,127,157,223,229,251,277,283,307,397,431,433,439,457,499, %T A364186 601,641,643,691,727,733,739,811,911,919,953,971,997,1013,1021,1051, %U A364186 1069,1093,1103,1163,1181,1327,1399,1423,1459,1471,1579,1597,1627,1657,1699,1709 %N A364186 Primes p such that p divides 2^((p-1)/x) - 1, where x is the smallest odd prime factor of p - 1. %D A364186 Allan Cunningham, Haupt-exponents of 2, The Quarterly Journal of Pure and Applied Mathematics, Vol. 37 (1906), pp. 122-145. %o A364186 (Magma) [p: p in PrimesUpTo(1709) | #Factorization(p-1) ge 2 and Modexp(2, Truncate((p-1)/Factorization(p-1)[2][1]), p) eq 1]; %o A364186 (PARI) forprime(p=2, 1709, v=Vec(factor(p-1))[1]; if(#v>1, t=0; e=v[2]; x=floor(p^(1/e))+1; until(x==p||t==2, if(Mod(x, p)^e==2, t++); x++); if(t==2, print1(p, ", ")))); %o A364186 (PARI) isok(p) = my(v=Vec(factor(p-1))[1]); isprime(p) && #v>1 && Mod(2, p)^((p-1)/v[2])==1; %Y A364186 Supersequence of A014752. %Y A364186 Cf. A059858, A270802, A360652. %K A364186 nonn %O A364186 1,1 %A A364186 _Arkadiusz Wesolowski_, Jul 15 2023