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 A118936 #8 Jul 17 2021 01:45:37
%S A118936 11,78,101,287,364,1001,1078,1096,1287,1364,10001,11096,18183,100001,
%T A118936 118183,336634,1000001,1336634,2727274,10000001,12727274,19138757,
%U A118936 23529412,25974026,97744361,100000001,120879122,123529412,140017878
%N A118936 Sub-Kaprekar numbers: k such that k = |q - r| and k^2 = q*10^m + r, for some m >= 1, q >= 0, 0 <= r < 10^m, with k not a power of 10.
%C A118936 Union of A118937 and A118938.
%e A118936 287^2 = 82369 and |82 - 369| = 287, so 287 is a term.
%e A118936 1287^2 = 1656369 and |1656 - 369| = 1287, so 1287 is a term.
%t A118936 f[n_] := !IntegerQ@Log[10,n] && Block[{p = 10^Range@Log[10,n^2]}, 0 == Times@@(n-Abs[Floor[n^2/p]-Mod[n^2,p]])]; Select[Range@400000,f]
%Y A118936 Cf. A006886, A118937, A118938.
%K A118936 base,nonn
%O A118936 1,1
%A A118936 _Giovanni Resta_, May 06 2006; corrected May 12 2006