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 A128024 #29 Jul 30 2023 03:42:28 %S A128024 3,7,19,109,131,607,863,2917,5923,12421,187507,353501,817519 %N A128024 Numbers k such that (7^k - 3^k)/4 is prime. %C A128024 All terms are primes. No other terms < 1000000. %H A128024 Jon Grantham and Andrew Granville, <a href="https://arxiv.org/abs/2307.07894">Fibonacci primes, primes of the form 2^n-k and beyond</a>, arXiv:2307.07894 [math.NT], 2023. %t A128024 k=4; Select[ Prime[ Range[1,200] ], PrimeQ[ ((k+3)^# - 3^#)/k ]& ] %o A128024 (PARI) forprime(p=3,1e5,if(ispseudoprime((7^p-3^p)/4),print1(p", "))) \\ _Charles R Greathouse IV_, Jun 01 2011 %o A128024 (Python) %o A128024 from sympy import isprime %o A128024 def aupto(lim): return [k for k in range(lim+1) if isprime((7**k-3**k)//4)] %o A128024 print(aupto(900)) # _Michael S. Branicky_, Mar 07 2021 %Y A128024 Cf. A028491, A057468, A059801, A121877. %Y A128024 Cf. A128025, A128026, A128027, A128028, A128029, A128030, A128031, A128032. %K A128024 hard,more,nonn %O A128024 1,1 %A A128024 _Alexander Adamchuk_, Feb 11 2007 %E A128024 a(8)-a(9) from _Farideh Firoozbakht_, Apr 08 2007 %E A128024 a(10) from _Robert Price_, Jun 01 2011 %E A128024 a(11)-a(13) from _Jon Grantham_, Jul 29 2023