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 A181232 #9 Jun 05 2025 19:39:36 %S A181232 0,24,6720,5644800,16388749440,172145618789760,6709378999665162240, %T A181232 988932080423985278515200,559938250258499272920457420800, %U A181232 1233183626500802426354472388092518400,10663689261713618730124837637890877517004800 %N A181232 Number of n X (n+2) binary matrices with all rows unique and all columns unique. %F A181232 a(n) = A181230(n,n+2). %Y A181232 Second subdiagonal of A181230. %Y A181232 Cf. A088310, A181231, A181233. %K A181232 nonn %O A181232 1,2 %A A181232 _R. H. Hardin_, Oct 10 2010