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 A180801 #6 Jun 02 2025 03:06:43
%S A180801 1,30,676,12502,163480,1687310,13449091,89142751,492505059,2376231744,
%T A180801 10047650419,38448350058,133156230854,427570371184,1270967124805,
%U A180801 3561662099758,9383313309748,23597905122682,56409558588283
%N A180801 Number of distinct solutions of sum{i=1..9}(x(2i-1)*x(2i)) = 0 (mod n), with x() in 0..n-1.
%C A180801 Column 9 of A180803
%H A180801 R. H. Hardin, <a href="/A180801/b180801.txt">Table of n, a(n) for n=1..183</a>
%e A180801 Solutions for sum of products of 9 0..1 pairs = 0 (mod 2) are
%e A180801 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0)
%e A180801 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 0*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 1*1 + 1*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 0*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 0*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 1*1 + 1*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*0 + 0*0 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1)
%e A180801 (0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*0 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1)
%e A180801 (0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1)
%e A180801 (0*0 + 0*1 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1)
%e A180801 (0*0 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1)
%e A180801 (0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1)
%e A180801 (0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1)
%e A180801 (0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1)
%e A180801 (0*1 + 0*1 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1)
%e A180801 (0*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1)
%K A180801 nonn
%O A180801 1,2
%A A180801 _R. H. Hardin_, suggested by _Max Alekseyev_ in the Sequence Fans Mailing List, Sep 20 2010