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 A105074 #18 Jan 12 2017 01:45:08 %S A105074 3,4,13,14,76,108,459,844 %N A105074 Number of ways to fill in an n X n grid such that the digits of each row and each column form a square number. %C A105074 Leading zeros are forbidden in the rows and columns. %e A105074 The 1 X 1 crosssquare-puzzle is easy; the only solutions are 1, 4, and 9. %e A105074 The 4 solutions for n=2 are [16/64], [36/64], [64/49], [81/16]. %e A105074 Or, writing them as 2 X 2 matrices, %e A105074 16 36 64 81 %e A105074 64 64 49 16 %K A105074 nonn,base,more %O A105074 1,1 %A A105074 _Matthijs Coster_, Apr 29 2005 %E A105074 Corrected and extended by _Luca Petrone_, Jan 08 2017