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 A115550 #6 Jul 15 2021 09:13:53 %S A115550 18,36,168,252,336,1668,3336,16668,33336,166668,333336,1666668, %T A115550 3333336,16666668,22222224,27777780,33333336,113149848,114678900, %U A115550 116207952,117737004,119266056,120795108,122324160,123853212 %N A115550 Numbers k such that k^2 is the concatenation of two numbers m and 8*m. %e A115550 18^2 = 3_24. %Y A115550 Cf. A102567, A106497, A115527 - A115556. %K A115550 nonn,base %O A115550 1,1 %A A115550 _Giovanni Resta_, Jan 25 2006