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 A180777 #5 Jun 02 2025 03:04:43 %S A180777 0,1,12,118,995,6518,32893,139369,499659,1599064,4551225,12014040, %T A180777 29034510,66658219,142828285,295240250,576393604,1098913338, %U A180777 1993354080,3560486370,6091808112,10312711744,16796812703,27247744649,42564714900 %N A180777 Number of distinct solutions of sum{i=1..6}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1. %C A180777 Column 6 of A180782 %H A180777 R. H. Hardin, <a href="/A180777/b180777.txt">Table of n, a(n) for n=1..183</a> %e A180777 Solutions for sum of products of 6 1..2 pairs = 0 (mod 3) are %e A180777 (1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1) (1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 2*2) %e A180777 (1*1 + 1*1 + 1*1 + 1*1 + 2*2 + 2*2) (1*1 + 1*1 + 1*1 + 1*2 + 1*2 + 1*2) %e A180777 (1*1 + 1*1 + 1*1 + 2*2 + 2*2 + 2*2) (1*1 + 1*1 + 1*2 + 1*2 + 1*2 + 2*2) %e A180777 (1*1 + 1*1 + 2*2 + 2*2 + 2*2 + 2*2) (1*1 + 1*2 + 1*2 + 1*2 + 2*2 + 2*2) %e A180777 (1*1 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2) (1*2 + 1*2 + 1*2 + 1*2 + 1*2 + 1*2) %e A180777 (1*2 + 1*2 + 1*2 + 2*2 + 2*2 + 2*2) (2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2) %K A180777 nonn %O A180777 1,3 %A A180777 _R. H. Hardin_ Sep 20 2010