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 A180799 #6 Jun 02 2025 03:06:31 %S A180799 1,20,270,3000,23282,151473,768541,3422978,12879078,44111410, %T A180799 133919379,381516366,988173838,2446846672,5633359713,12527643860, %U A180799 26226659375,53655084387,104124710377,198817175068,363133886202,654527617329 %N A180799 Number of distinct solutions of sum{i=1..7}(x(2i-1)*x(2i)) = 0 (mod n), with x() in 0..n-1. %C A180799 Column 7 of A180803 %H A180799 R. H. Hardin, <a href="/A180799/b180799.txt">Table of n, a(n) for n=1..183</a> %e A180799 Solutions for sum of products of 7 0..1 pairs = 0 (mod 2) are %e A180799 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0) %e A180799 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*1) %e A180799 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 0*1) %e A180799 (0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 0*1) %e A180799 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 1*1 + 1*1) %e A180799 (0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 1*1 + 1*1) %e A180799 (0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 0*1) %e A180799 (0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 1*1 + 1*1) %e A180799 (0*0 + 0*0 + 0*0 + 1*1 + 1*1 + 1*1 + 1*1) %e A180799 (0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1) %e A180799 (0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1) %e A180799 (0*0 + 0*0 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1) %e A180799 (0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1) %e A180799 (0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1) %e A180799 (0*0 + 0*1 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1) %e A180799 (0*0 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1) %e A180799 (0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1) %e A180799 (0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1) %e A180799 (0*1 + 0*1 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1) %e A180799 (0*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1) %K A180799 nonn %O A180799 1,2 %A A180799 _R. H. Hardin_, suggested by _Max Alekseyev_ in the Sequence Fans Mailing List, Sep 20 2010