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 A115442 #7 Nov 02 2024 19:33:24
%S A115442 8,7312,8991,32524,67477,76568,4891730,5108271,8528094,71588336,
%T A115442 98999901,399659933007,600340066994,723627738227,877712329768,
%U A115442 998999999001,3485626998114,3787100274614,6212899725387,6514373001887
%N A115442 Numbers whose square is the concatenation of two numbers k and k-2.
%e A115442 8083_8081 = 8991^2.
%t A115442 Select[Table[Sqrt[k*10^IntegerLength[k]+k-2],{k,4,86*10^5}],IntegerQ] (* The program generates the first 9 terms of the sequence. *) (* _Harvey P. Dale_, Nov 02 2024 *)
%Y A115442 Cf. A030467, A106497, A115431, A115427, A115438, A115439, A115440, A115441, A115443, A115444, A115445, A115446, A115447.
%K A115442 base,nonn
%O A115442 1,1
%A A115442 _Giovanni Resta_, Jan 24 2006