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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A226307 a(n) = Sum_{k >= 0} binomial(6*n,k)*binomial(3*n,k)*binomial(2*n,k). 0
 1, 37, 6229, 1454473, 393638933, 115921649662, 36059466046681, 11656478429182365, 3876878952705468437, 1318042625299425997138, 455984891164728575299354, 160005530292143438293125981, 56811170133331347049469683481, 20372514849857567410065222675568, 7367851599324133697992581931476613 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Table of n, a(n) for n=0..14. Mark C. Wilson, Diagonal asymptotics for products of combinatorial classes, 2013. FORMULA a(n) ~ 2^(6*n) * 3^(9*n-1) / (Pi^(3/2) * n^(3/2) * 5^(5*n - 1/2)). - Vaclav Kotesovec, Aug 04 2022 MATHEMATICA Table[Sum[Binomial[6n, k]Binomial[3n, k]Binomial[2n, k], {k, 0, n}], {n, 0, 20}] (* Harvey P. Dale, May 29 2014 *) CROSSREFS Sequence in context: A183481 A295415 A202801 * A296598 A221034 A221498 Adjacent sequences: A226304 A226305 A226306 * A226308 A226309 A226310 KEYWORD nonn AUTHOR N. J. A. Sloane, Jun 07 2013 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 April 22 12:13 EDT 2024. Contains 371900 sequences. (Running on oeis4.)