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 A263539 #5 Oct 31 2015 15:02:10 %S A263539 3,5,17,257,65537,73014444017,7839866227890585600377, %T A263539 90965983657404652017189201081165598949585237, %U A263539 59265532390032181385721703100931439246761487956490653915298719426194939212611074425177277 %N A263539 Smallest odd prime of the form k*a(n-1)*a(n-2)*...*a(1) + 2. %C A263539 Infinite sequence of primes which coincides with Fermat primes, a(n) = A019434(n-1), only for n <= 5. %C A263539 For the k values, see A263540. %o A263539 (PARI) terms=12; p=1; for(n=1, terms, q=p+2; while(!ispseudoprime(q), q+=2*p); print1(q, ", "); p*=q) %Y A263539 Cf. A071580, A090475, A263540, A019434. %K A263539 nonn %O A263539 1,1 %A A263539 _Jeppe Stig Nielsen_, Oct 20 2015