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 A076200 #7 Mar 24 2025 22:34:34 %S A076200 1,1,2,0,2,5,2,5,2,11,4,17,8,43,2,19,2,19,4,13,32,23,4,47,2,37,74,23, %T A076200 86,43,122,149,128,19,146,29,226,31,64,53,2,23,134,43,268,103,134,59, %U A076200 64,43,4,101,16,61,346,229,278,103,16,41,64,127,2,181,302,151,146,191,262 %N A076200 a(n) equals the least s>0 such that n!! + s^3 is prime, or 0 if there is no such prime. %e A076200 a(4)=0 because 4!! = A006882(4) = 8 has algebraic factorization 8 + s^3 = (2 + s) * (4 - 2*s + s^2), thus can never be prime for any s. - _Sean A. Irvine_, Mar 24 2025 %Y A076200 Cf. A006882, A057019. %K A076200 nonn %O A076200 1,3 %A A076200 _Zak Seidov_, Nov 02 2002 %E A076200 Missing a(4)=0 inserted by _Sean A. Irvine_, Mar 24 2025