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 A090874 #14 Aug 27 2022 18:25:36 %S A090874 1,1,1,1,1,1806390369,218327374070,3697211121741701604 %N A090874 a(n) is the smallest number m such that m^2^k + (m+1)^2^k is prime for k=0..n. %C A090874 The first five terms of this sequence correspond to Fermat primes. %e A090874 a(5)=1806390369 because this is the smallest number m such that m^2^k + (m+1)^2^k is prime for k=0,1,2,3,4 and 5. %Y A090874 Cf. A090872, A090873, A019434, A000215. %K A090874 nonn,hard,more %O A090874 0,6 %A A090874 _Farideh Firoozbakht_, Feb 06 2004 %E A090874 a(6) found by Kellen Shenton added by _Jeppe Stig Nielsen_, Mar 28 2022 %E A090874 a(7) from _Kellen Shenton_, Aug 27 2022