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 A188451 #6 Jul 22 2025 11:13:12 %S A188451 0,0,5,139,4944,244490,15980350,1330789145,137418347276,17218246261956 %N A188451 Number of (3*n)Xn binary arrays with nonzero rows in decreasing order, no more than 3 ones in any row and exactly 3 ones in every column. %C A188451 Row 3 of A188449 %e A188451 All solutions for 9X3 %e A188451 ..1..1..1....1..1..1....1..1..0....1..1..1....1..1..1 %e A188451 ..1..0..1....1..1..0....1..0..1....1..1..0....1..1..0 %e A188451 ..1..0..0....1..0..1....1..0..0....1..0..0....1..0..1 %e A188451 ..0..1..1....0..1..0....0..1..1....0..1..1....0..1..1 %e A188451 ..0..1..0....0..0..1....0..1..0....0..0..1....0..0..0 %e A188451 ..0..0..0....0..0..0....0..0..1....0..0..0....0..0..0 %e A188451 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %e A188451 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %e A188451 ..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0 %K A188451 nonn %O A188451 1,3 %A A188451 _R. H. Hardin_ Mar 31 2011