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 A086323 #9 Dec 28 2015 09:32:48 %S A086323 1,2,6,8,30,36,126,160,450,740,2046,2592,8190,12824,30030,48640, %T A086323 131070,194508,524286,812840,1987818,3486824,8388606,12400368, %U A086323 33348150,56700072,128800098,219681672,536870910,861181320,2147483646,3555730432 %N A086323 Number of n X n circulant invertible (0,1) matrices over the reals. %H A086323 Max Alekseyev, <a href="/A086323/b086323.txt">Table of n, a(n) for n = 1..39</a> %F A086323 a(n) = 2^n - A086328(n). %Y A086323 Cf. A003473. %K A086323 nonn %O A086323 1,2 %A A086323 Yuval Dekel (dekelyuval(AT)hotmail.com), Aug 30 2003 %E A086323 More terms from _Vladeta Jovovic_, Sep 08 2003 %E A086323 More terms from _Max Alekseyev_, Sep 24 2009