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 A256302 #12 Apr 06 2015 10:05:52 %S A256302 2,5,5,5,11,11,11,11,11,11,23,23,23,23,23,23,23,23,23,23,23,23 %N A256302 Least prime p such that p+3*k*(k+1) is prime for all k=0,...,n. %C A256302 Inspired by the so-called prime-generating polynomials. %C A256302 Since p | 3n(n+1) for n=p-1, one has a(n) > p(n). Otherwise stated, a(p-1) = p (as, e.g., for p=23) is optimal. %o A256302 (PARI) a(n)=forprime(p=1,,for(i=1,n,ispseudoprime(p+3*(i+1)*i)||next(2));return(p)) %Y A256302 Cf. A181963, A181969, A181973, A210626, A211773, A212325, ... %Y A256302 Cf. A005846, A056561. %Y A256302 Cf. A256300, A256301. %K A256302 nonn,more %O A256302 0,1 %A A256302 _M. F. Hasler_, Apr 05 2015