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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A180776 Number of distinct solutions of sum{i=1..5}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1 1
0, 0, 7, 62, 402, 1960, 7587, 25470, 73146, 193036, 455161, 1022770, 2098782, 4196208, 7797217, 14286908, 24527232, 42125055, 67955391, 110571248, 170260213, 264585538, 390623343, 588725404, 837466268, 1220597598, 1696535256 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Column 5 of A180782

LINKS

R. H. Hardin, Table of n, a(n) for n=1..249

EXAMPLE

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

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

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

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

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

CROSSREFS

Sequence in context: A254121 A047685 A171078 * A024089 A327588 A287481

Adjacent sequences:  A180773 A180774 A180775 * A180777 A180778 A180779

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 September 24 07:28 EDT 2020. Contains 337317 sequences. (Running on oeis4.)