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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A011917 [ n(n-1)(n-2)(n-3)/7 ]. 0
0, 0, 0, 0, 3, 17, 51, 120, 240, 432, 720, 1131, 1697, 2451, 3432, 4680, 6240, 8160, 10491, 13289, 16611, 20520, 25080, 30360, 36432, 43371, 51257, 60171, 70200, 81432, 93960, 107880, 123291, 140297, 159003 (list; graph; refs; listen; history; internal format)
OFFSET

0,5

FORMULA

a(n) = +4*a(n-1) -6*a(n-2) +4*a(n-3) -a(n-4) +a(n-7) -4*a(n-8) +6*a(n-9) -4*a(n-10) +a(n-11). G.f.: x^4*(3+5*x+x^2+6*x^3+x^4+5*x^5+3*x^6) / ( (1-x)^5*(1+x+x^2+x^3+x^4+x^5+x^6) ). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 15 2010]

CROSSREFS

Sequence in context: A144640 A084069 A132124 * A018691 A163943 A174285

Adjacent sequences:  A011914 A011915 A011916 * A011918 A011919 A011920

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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

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

Last modified February 14 20:38 EST 2012. Contains 205663 sequences.