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 A239548 #9 Feb 16 2025 08:33:21 %S A239548 2,179,239,359,419,487,659,719,883,1013,1019,1439,1459,1499,1559,1723, %T A239548 1871,1993,2039,2339,2399,2459,2593,2699,2819,2939,3041,3299,3329, %U A239548 3359,3539,3779,4019,4813,4919,4957,5039,5231,5261,5279,5399,5639,6011,6353,6373 %N A239548 Primes p such that gcd(Lucas(p), Mersenne(p)) > 1. %H A239548 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LucasNumber.html">Lucas Number</a> %H A239548 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/MersenneNumber.html">Mersenne Number</a> %e A239548 239 is in the sequence since it is prime and 479 is a prime factor of both Lucas(239) and Mersenne(239) = 2^239 - 1. %o A239548 (Magma) [p: p in PrimesUpTo(6500) | Gcd(Lucas(p),2^p-1) gt 1]; %o A239548 (PARI) for(p=2, 6373, if(isprime(p)&&gcd(fibonacci(p-1)+fibonacci(p+1), 2^p-1)>1, print1(p, ", "))); %Y A239548 Supersequence of A230809. %Y A239548 Cf. A000032, A001348. %K A239548 nonn %O A239548 1,1 %A A239548 _Arkadiusz Wesolowski_, Mar 21 2014