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 A252074 #6 Jun 02 2025 10:45:54 %S A252074 3279,23091,206747,1669294,13460641,110131513,896763044,7301549024, %T A252074 59570598626,485457428288,3954090473063,32222610105491, %U A252074 262627685087219,2140187356615074,17439608164244761,142114394703257745 %N A252074 Number of (n+2)X(7+2) 0..2 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 3 or 4. %C A252074 Column 7 of A252075 %H A252074 R. H. Hardin, <a href="/A252074/b252074.txt">Table of n, a(n) for n = 1..210</a> %e A252074 Some solutions for n=2 %e A252074 ..2..1..2..2..2..1..2..2..2....2..2..1..2..2..2..2..2..2 %e A252074 ..2..2..2..1..2..2..2..2..2....2..2..2..2..1..2..2..1..2 %e A252074 ..1..2..2..2..2..2..2..2..2....2..2..2..2..2..2..2..2..2 %e A252074 ..2..2..2..2..2..2..1..2..2....2..1..2..2..2..2..2..2..2 %K A252074 nonn %O A252074 1,1 %A A252074 _R. H. Hardin_, Dec 13 2014