login
This site is supported by donations to The OEIS Foundation.

 

Logo

Many excellent designs for a new banner were submitted. We will use the best of them in rotation.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A178465 Expansion of -2*x^2*(-3-2*x+x^2-x^3-2*x^4+x^5)  /  ( (1+x)^2*(x-1)^4 ). 2
0, 0, 6, 16, 36, 66, 114, 176, 264, 370, 510, 672, 876, 1106, 1386, 1696, 2064, 2466, 2934, 3440, 4020, 4642, 5346, 6096, 6936, 7826, 8814, 9856, 11004, 12210, 13530, 14912, 16416, 17986, 19686, 21456, 23364, 25346, 27474, 29680, 32040, 34482 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..41.

FORMULA

For n even, a(n) = n*(2+n^2)/2 = A061804(n/2). For n>1 and odd, a(n)=(n+1)*(n^2-n+2)/2 = 2*A212133((n+1)/2).

a(n) = (2-2*(-1)^n+(3+(-1)^n)*n+2*n^3)/4 for n>1. [Colin Barker, Feb 18 2013]

MATHEMATICA

CoefficientList[ Series[ 2x^2 (3 + 2x - x^2 + x^3 + 2x^4 - x^5)/((1 + x)^2 (x - 1)^4), {x, 0, 42}], x] (* Robert G. Wilson v, Feb 17 2014 *)

CROSSREFS

Cf. A187062, A187397, A061804, A018808.

Sequence in context: A160997 A199629 A098943 * A120586 A171373 A048487

Adjacent sequences:  A178462 A178463 A178464 * A178466 A178467 A178468

KEYWORD

nonn

AUTHOR

Sean A. Irvine, Mar 23 2011

EXTENSIONS

Discrepancy with A018808 resolved. David W. Wilson, Aug 05 2013

First line of formulas corrected. R. J. Mathar, Aug 05 2013

Prepended a(0)=0, Joerg Arndt, Feb 19 2014

STATUS

approved

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

Content is available under The OEIS End-User License Agreement .

Last modified April 23 19:18 EDT 2014. Contains 240946 sequences.