login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A242983 n/2 * (n^3 - 2*n^2 - 2*n + 5). 0
0, 1, 1, 12, 58, 175, 411, 826, 1492, 2493, 3925, 5896, 8526, 11947, 16303, 21750, 28456, 36601, 46377, 57988, 71650, 87591, 106051, 127282, 151548, 179125, 210301, 245376, 284662, 328483, 377175, 431086, 490576, 556017 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
COMMENTS
For n>1, number of ways to place two dominoes horizontally on an n X n chessboard.
LINKS
FORMULA
a(n) = A019582(n) + A077414(n-2), n>1.
G.f.: x*(-2*x^3 + 17*x^2 - 4*x + 1) / (1-x)^5.
MATHEMATICA
Table[n/2 (n^3-2n^2-2n+5), {n, 0, 40}] (* or *) LinearRecurrence[{5, -10, 10, -5, 1}, {0, 1, 1, 12, 58}, 40] (* Harvey P. Dale, Jul 19 2018 *)
CROSSREFS
Sequence in context: A072259 A272233 A283164 * A167533 A244907 A062477
KEYWORD
nonn,easy
AUTHOR
Ralf Stephan, Jun 09 2014
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 19 22:34 EDT 2024. Contains 374441 sequences. (Running on oeis4.)