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

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A105251 a(n) = binomial(n+4,n)*binomial(n+8,n). 1
 1, 45, 675, 5775, 34650, 162162, 630630, 2123550, 6370650, 17381650, 43801758, 103169430, 229265400, 484306200, 978496200, 1900457064, 3563356995, 6473226375, 11428041625, 19658764125, 33026723730, 54295634250, 87501228750, 138447123750, 215362192500 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS T. D. Noe, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (13,-78,286,-715,1287,-1716,1716,-1287,715,-286,78,-13,1). FORMULA G.f.: -(70*x^4+224*x^3+168*x^2+32*x+1)/(x-1)^13. - Colin Barker, Jan 21 2013 From Amiram Eldar, Sep 01 2022: (Start) Sum_{n>=0} 1/a(n) = 640*Pi^2 - 13925728/2205. Sum_{n>=0} (-1)^n/a(n) = 640*Pi^2/3 - 90112*log(2)/105 + 471984/1225. (End) EXAMPLE a(0): C(0+4,0)*C(0+8,0) = C(4,0)*C(8,0) = 1*1 = 1; a(10): C(10+4,10)*C(10+8,10) = C(14,10)*(18,10) = 1001*43758 = 43801758. MATHEMATICA f[n_] := Binomial[n + 4, n]Binomial[n + 8, n]; Table[ f[n], {n, 0, 22}] (* Robert G. Wilson v, Apr 20 2005 *) PROG (Magma) [Binomial(n+4, n)*Binomial(n+8, n): n in [0..30]]; // Vincenzo Librandi, Jul 31 2015 CROSSREFS Sequence in context: A160234 A110691 A296540 * A099632 A264138 A293971 Adjacent sequences: A105248 A105249 A105250 * A105252 A105253 A105254 KEYWORD easy,nonn AUTHOR Zerinvary Lajos, Apr 14 2005 EXTENSIONS More terms from Robert G. Wilson v, Apr 20 2005 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 December 3 11:54 EST 2022. Contains 358521 sequences. (Running on oeis4.)