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 A207934 #8 Jul 22 2025 21:01:27 %S A207934 2,16,98,643,5594,58602,737575,10609482,171524786,3063622641, %T A207934 59875563176,1270299719270,29076260441101,714274071132328, %U A207934 18746674985446278,523589036696879095,15507197067809135806,485494086155807224584 %N A207934 Number of n X n 0..1 arrays avoiding 0 0 1 and 1 0 0 horizontally and 0 0 1 and 1 1 0 vertically. %C A207934 Diagonal of A207938 %e A207934 Some solutions for n=4 %e A207934 ..1..0..1..0....0..0..0..0....1..0..1..1....0..0..0..0....1..1..1..1 %e A207934 ..1..1..1..1....0..0..0..0....0..1..0..1....1..0..1..1....1..1..1..1 %e A207934 ..1..1..1..1....0..0..0..0....0..1..0..1....0..0..0..0....1..1..1..1 %e A207934 ..1..1..1..1....0..0..0..0....0..1..0..1....0..0..0..0....1..1..1..1 %K A207934 nonn %O A207934 1,1 %A A207934 _R. H. Hardin_ Feb 21 2012