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 A374091 #32 Jun 29 2024 11:17:47 %S A374091 0,5,11,605,209,73205,2299,8857805,6061,218405,278179 %N A374091 a(n) is the smallest nonnegative integer k where exactly n ordered pairs of positive integers (x, y) exist such that x^2 + 3*x*y + y^2 = k. %C A374091 a(n) is the smallest nonnegative k such that A374089(k) = n. %C A374091 a(n) is of the form 5*k^2 if and only if n is odd. %C A374091 a(12) = 66671. %C A374091 a(14) = 5285401. %C A374091 a(15) = 26427005. %C A374091 a(16) = 187891. %C A374091 a(18) = 1266749. %C A374091 a(20) = 8067191. %C A374091 a(21) = 3197667605. - _Chai Wah Wu_, Jun 29 2024 %C A374091 a(24) = 2066801. %C A374091 a(26) = 36735721. %C A374091 a(27) = 183678605. - _Chai Wah Wu_, Jun 28 2024 %F A374091 a(2*n) = A374095(n). %F A374091 a(n) <= 5*11^(n-1) for all n >= 1. - _Jason Yuen_, Jun 29 2024 %Y A374091 Cf. A328151, A374090. %Y A374091 Cf. A374089, A374095. %K A374091 nonn,more %O A374091 0,2 %A A374091 _Seiichi Manyama_, Jun 28 2024