A180773 Number of distinct solutions of sum{i=1..2}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1

0, 1, 2, 6, 13, 23, 36, 62, 78, 123, 150, 238, 255, 355, 427, 567, 580, 864, 810, 1202, 1232, 1471, 1452, 2310, 1960, 2479, 2712, 3414, 2947, 4649, 3600, 5126, 5022, 5673, 5845, 8457, 6165, 7975, 8405, 11062, 8410, 13133, 9702, 13726, 14475, 14323, 12696

Offset

1,3

Comments

Column 2 of A180782

Links

R. H. Hardin, Table of n, a(n) for n=1..999

Example

Solutions for sum of products of 2 1..5 pairs = 0 (mod 6) are
(1*1 + 1*5) (1*2 + 1*4) (1*2 + 2*2) (1*2 + 2*5) (1*2 + 4*4) (1*3 + 1*3)
(1*3 + 3*3) (1*3 + 3*5) (1*4 + 2*4) (1*4 + 4*5) (1*5 + 5*5) (2*2 + 2*4)
(2*2 + 4*5) (2*3 + 2*3) (2*3 + 3*4) (2*4 + 2*5) (2*4 + 4*4) (2*5 + 4*5)
(3*3 + 3*3) (3*3 + 3*5) (3*4 + 3*4) (3*5 + 3*5) (4*4 + 4*5)

Crossrefs

Sequence in context: A064960 A293503 A143689 * A011891 A370880 A184533

Adjacent sequences: A180770 A180771 A180772 * A180774 A180775 A180776

Keyword

nonn

Author

R. H. Hardin Sep 20 2010

Status

approved