login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A180774 Number of distinct solutions of sum{i=1..3}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1 1
0, 0, 5, 14, 42, 119, 253, 526, 944, 1702, 2655, 4510, 6284, 9867, 13519, 19980, 25128, 37286, 44562, 63802, 76850, 102370, 118591, 168208, 183320, 241554, 279852, 359754, 387016, 528861, 543620, 712450, 780810, 953120, 1025355, 1360255 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Column 3 of A180782

LINKS

R. H. Hardin, Table of n, a(n) for n=1..447

EXAMPLE

Solutions for sum of products of 3 1..3 pairs = 0 (mod 4) are

(1*1 + 1*1 + 1*2) (1*1 + 1*1 + 2*3) (1*1 + 1*2 + 3*3) (1*1 + 1*3 + 2*2)

(1*1 + 2*3 + 3*3) (1*2 + 1*2 + 2*2) (1*2 + 1*3 + 1*3) (1*2 + 2*2 + 2*3)

(1*2 + 3*3 + 3*3) (1*3 + 1*3 + 2*3) (1*3 + 2*2 + 3*3) (2*2 + 2*2 + 2*2)

(2*2 + 2*3 + 2*3) (2*3 + 3*3 + 3*3)

CROSSREFS

Sequence in context: A266941 A034549 A232492 * A210972 A197607 A296829

Adjacent sequences:  A180771 A180772 A180773 * A180775 A180776 A180777

KEYWORD

nonn

AUTHOR

R. H. Hardin Sep 20 2010

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 16 00:05 EST 2021. Contains 340195 sequences. (Running on oeis4.)