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 A213797 #6 Jun 02 2025 08:03:53 %S A213797 1,6,96,9522,4843626,13937940952,212962858290086 %N A213797 Number of n X n 0..5 symmetric arrays with every row summing to floor(n*5/2). %C A213797 Column 5 of A213800 %e A213797 Some solutions for n=4 %e A213797 ..1..3..2..4....5..1..0..4....4..1..0..5....5..4..0..1....5..3..1..1 %e A213797 ..3..3..1..3....1..5..4..0....1..1..5..3....4..4..0..2....3..3..4..0 %e A213797 ..2..1..5..2....0..4..2..4....0..5..3..2....0..0..5..5....1..4..0..5 %e A213797 ..4..3..2..1....4..0..4..2....5..3..2..0....1..2..5..2....1..0..5..4 %K A213797 nonn %O A213797 1,2 %A A213797 _R. H. Hardin_ Jun 20 2012