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 A109203 #4 Mar 30 2012 18:40:28 %S A109203 2,3,3,14,3,2,1,5,7,1,1,4,5,1,3,7,1,10,1,11,1,4,1,6,13,3,1,20,1,4,11, %T A109203 4,1,1,1,16,5,5,1,4,3,6,1,1,15,4,5,1,17,4,1,1,1,1,11,4,1,14,1,10,1,14, %U A109203 7,4,15,4,1,4,1,1,1,9,1,15,9,8,9,10,5,14,3,1,5,6,1,3,19,14,5,6,41,4,1,14,1 %N A109203 Minimal value of k>0 such that n^8 + k^2 is a semiprime. %C A109203 There seems to be a modest correlation with the n^7 sequence (A109202) with often the same values [n = 10,16,18,23,31,45,52,55,66,72,82,88,100]. Sometimes the same value of k occurs for the n^6 sequence (A109201), the n^7 sequence (A109202) and this n^8 sequence, for instance n=88, k=5. The statistics of these sequences is unclear, as are the asymptotics. %e A109203 a(0) = 2 because 0^8 + 1^2 = 1 is not semiprime, but 0^8 + 2^2 = 4 = 2^2 is. %e A109203 a(1) = 3 because 1^8 + 1^2 and 1^8 + 2^2 are not semiprime, but 1^8 + 3^2 = 10 = 2 * 5 is semiprime. %e A109203 a(2) = 3 because 2^8 + 3^2 = 265 = 5 * 53 is semiprime, but 2^8 + 1^2 and 2^8 + 2^2 are not semiprimes. %e A109203 a(90) = 41 because 90^8 + 41^2 = 4304672100001681 = 6317 * 681442472693 and for no smaller k>0 is 90^8 + k^2 a semiprime. %e A109203 a(100) = 9 because 100^8 + 9^2 = 10000000000000081 = 34361 * 291027618521 and for no smaller k>0 is 100^8 + k^2 a semiprime. %Y A109203 Cf. A001358, A108714, A109197, A109198, A109199, A109200, A109201, A109202. %K A109203 easy,nonn %O A109203 0,1 %A A109203 _Jonathan Vos Post_, Jul 03 2005