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 A066300 #19 Dec 17 2016 10:30:23
%S A066300 0,1,27,1296,100000,11390625,1801088541,377801998336,101559956668416,
%T A066300 34050628916015625,13931233916552734375,6831675453247426400256,
%U A066300 3955759092264800909058048,2670419511272061205254504361
%N A066300 Number of n X n matrices with exactly 2 1's in each row, other entries 0.
%F A066300 a(n) = binomial(n,2)^n.
%t A066300 Table[ Binomial[n, 2]^n, {n, 1, 16} ]
%o A066300 (PARI) a(n) = binomial(n,2)^n \\ _Charles R Greathouse IV_, Dec 16 2016
%Y A066300 Cf. A001499.
%K A066300 nonn
%O A066300 1,3
%A A066300 Sharon Sela (sharonsela(AT)hotmail.com), Jan 01 2002
%E A066300 More terms from _Robert G. Wilson v_, Jan 03 2002