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 A109200 #7 Jun 16 2016 16:58:46 %S A109200 2,3,1,2,7,3,5,16,3,4,1,10,1,2,3,8,1,2,5,10,3,2,1,8,5,4,9,2,9,3,13,8, %T A109200 15,8,7,2,5,2,3,16,3,9,31,14,3,4,3,10,11,2,3,2,9,12,5,4,3,10,5,6,11,6, %U A109200 9,16,5,28,19,4,3,16,3,6,7,4,9,28,9,6,11,12,7,10,7,14,29,3,11,8,3,18,7,8,3,4 %N A109200 Minimal value of k>0 such that n^5 + k^2 is a semiprime. %F A109200 a(n) = minimal value of k>0 such that n^5 + k^2 is a semiprime. %e A109200 a(0) = 2 because 0^5 + 1^2 = 1 is not semiprime, but 0^5 + 2^2 = 4 = 2^2 is. %e A109200 a(1) = 3 because 1^5 + 1^2 and 1^5 + 2^2 are not semiprime, but 1^5 + 3^2 = 10 = 2 * 5 is semiprime. %e A109200 a(2) = 1 because 2^5 + 1^2 = 33 = 3 * 11 is semiprime. %e A109200 a(42) = 31 because 42^5 + 31^2 = 130692193 = 571 * 228883 and for no smaller k>0 is 42^4 + k^2 a semiprime. %t A109200 a[n_] := (For[k = 1, PrimeOmega[n^5 + k^2] != 2, k++]; k); a /@ Range[0, 93] (* _Giovanni Resta_, Jun 16 2016 *) %Y A109200 Cf. A001358, A108714, A109197, A109198, A109199. %K A109200 easy,nonn %O A109200 0,1 %A A109200 _Jonathan Vos Post_, Jun 26 2005 %E A109200 a(46) corrected by _Giovanni Resta_, Jun 16 2016