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

 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 Table of n, a(n) for n=0..33. Index entries for sequences related to dominoes Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1). 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 Cf. A242856, A242861. Sequence in context: A072259 A272233 A283164 * A167533 A244907 A062477 Adjacent sequences: A242980 A242981 A242982 * A242984 A242985 A242986 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.

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