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 A115435 #5 Jul 15 2021 06:22:39 %S A115435 2137,2892,6369,12217,21964,28233,42312,4978977,9571608,18642249, %T A115435 32288908,96039609,200037461217,305526508312,570666416233, %U A115435 638912248204,996003996009,1846991026584,3251664327537,4859838227992 %N A115435 Numbers k such that the concatenation of k with k-8 gives a square. %e A115435 18642249_18642241 = 43176671^2. %Y A115435 Cf. A030465, A102567, A115426, A115437, A115428, A115429, A115430, A115431, A115432, A115433, A115434, A115436, A115446. %K A115435 base,nonn %O A115435 1,1 %A A115435 _Giovanni Resta_, Jan 25 2006