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 A063898 #10 Sep 28 2013 08:08:36 %S A063898 2,2,2,14,14,14,66746,475424,12124166,14899339904 %N A063898 Smallest k > 0 such that k + F_n are all primes, where F_n is the n-th Fermat number. %C A063898 Is this sequence finite? %e A063898 For j=3 a(3)=2 because 257+2, 17+2, 5+2, 3+2 are all primes. %e A063898 For j=4 a(4)=14 because 65537+14, 257+14, 17+14, 5+14, 3+14 are all primes. %o A063898 (PARI) okprimep(mink, vecf) = {for (i=1, #vecf, if (! isprime(mink + vecf[i]), return (0));); return (1);} %o A063898 a(n) = {mink = 1; vecf = vector(n+1, i, 2^(2^(i-1)) + 1); while (! okprimep(mink, vecf), mink++); mink;} \\ _Michel Marcus_, Sep 28 2013 %Y A063898 Cf. A000215 (Fermat numbers). %K A063898 hard,more,nonn %O A063898 0,1 %A A063898 _Felice Russo_, Aug 29 2001 %E A063898 a(10) from _Donovan Johnson_, Oct 12 2008