# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a180789 Showing 1-1 of 1 %I A180789 #3 Mar 31 2012 12:35:46 %S A180789 0,1,15,198,2282,19300,126861,670058,2997685,11539243,39660969, %T A180789 122371876,348412793,914595808,2264326584,5259342780,11692554312, %U A180789 24683815072,50403390786,98560661538,187881799209,345060981679,621482071341 %N A180789 Number of distinct solutions of sum{i=1..7}(x(2i-1)*x(2i)) = 1 (mod n), with x() only in 1..n-1 %C A180789 Column 7 of A180793 %H A180789 R. H. Hardin, Table of n, a(n) for n=1..183 %e A180789 Solutions for sum of products of 7 1..2 pairs = 1 (mod 3) are %e A180789 (1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1) %e A180789 (1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 2*2) %e A180789 (1*1 + 1*1 + 1*1 + 1*1 + 1*2 + 1*2 + 1*2) %e A180789 (1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 2*2 + 2*2) %e A180789 (1*1 + 1*1 + 1*1 + 1*1 + 2*2 + 2*2 + 2*2) %e A180789 (1*1 + 1*1 + 1*1 + 1*2 + 1*2 + 1*2 + 2*2) %e A180789 (1*1 + 1*1 + 1*1 + 2*2 + 2*2 + 2*2 + 2*2) %e A180789 (1*1 + 1*1 + 1*2 + 1*2 + 1*2 + 2*2 + 2*2) %e A180789 (1*1 + 1*1 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2) %e A180789 (1*1 + 1*2 + 1*2 + 1*2 + 1*2 + 1*2 + 1*2) %e A180789 (1*1 + 1*2 + 1*2 + 1*2 + 2*2 + 2*2 + 2*2) %e A180789 (1*1 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2) %e A180789 (1*2 + 1*2 + 1*2 + 1*2 + 1*2 + 1*2 + 2*2) %e A180789 (1*2 + 1*2 + 1*2 + 2*2 + 2*2 + 2*2 + 2*2) %e A180789 (2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2) %K A180789 nonn %O A180789 1,3 %A A180789 _R. H. Hardin_ Sep 20 2010 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE