A180829 Number of distinct solutions of sum{i=1..6}(x(2i-1)*x(2i)) = 1 (mod n), with x() only in 2..n-2

0, 0, 0, 0, 7, 55, 715, 4260, 25603, 102717, 408766, 1258601, 3851049, 9814876, 25170369, 55987636, 125991305, 252719186, 515720550, 954717615, 1803406803, 3129204953, 5559159252, 9151697254, 15453087022, 24346596138, 39398858317

Offset

1,5

Comments

Column 6 of A180834

Links

R. H. Hardin, Table of n, a(n) for n=1..183

Example

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

Crossrefs

Sequence in context: A209668 A340028 A365030 * A227544 A094656 A239156

Adjacent sequences: A180826 A180827 A180828 * A180830 A180831 A180832

Keyword

nonn

Author

R. H. Hardin Sep 20 2010

Status

approved