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 A201983 #8 Jul 22 2025 16:25:21 %S A201983 1,77,134217,7375608084,13189629907532856 %N A201983 Number of n X n zero-sum -3..3 arrays with rows and columns lexicographically nondecreasing. %C A201983 Diagonal of A201989 %e A201983 Some solutions for n=3 %e A201983 .-3.-3..1...-3.-1..0...-3..1..3...-3.-3..1...-3.-1..2...-3..0..2...-1.-1..0 %e A201983 ..2..2.-2....0.-1..2...-3..2..0...-3..2..3...-1..1..0...-1..2.-2...-1..2.-3 %e A201983 ..2..3.-2....2.-1..2...-2.-1..3...-2..2..3....3.-2..1....1.-1..2....2..2..0 %K A201983 nonn %O A201983 1,2 %A A201983 _R. H. Hardin_ Dec 07 2011