The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A006587 a(n) = 3*2^(2*n)*(3*n)!/((2*n)!*n!). 1
 3, 36, 720, 16128, 380160, 9225216, 228114432, 5715394560, 144599482368, 3685869158400, 94513444945920, 2435255516528640, 62999001405849600, 1635260233414606848, 42568679092062781440, 1110895735754245275648 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 REFERENCES W. A. Whitworth, DCC Exercises in Choice and Chance, Stechert, NY, 1945, p. 35. LINKS M. Le Brun, Email to N. J. A. Sloane, Jul 1991 MAPLE A006587:=n->3*2^(2*n)*(3*n)!/((2*n)!*n!); seq(A006587(n), n=0..50); # Wesley Ivan Hurt, Nov 23 2013 MATHEMATICA Table[3*2^(2n)(3n)!/((2n)!*n!), {n, 0, 50}] (* Wesley Ivan Hurt, Nov 23 2013 *) PROG (PARI) a(n)=3*binomial(3*n, n)*4^n \\ Charles R Greathouse IV, Aug 11 2017 CROSSREFS Sequence in context: A223912 A224184 A241996 * A328122 A091482 A121245 Adjacent sequences:  A006584 A006585 A006586 * A006588 A006589 A006590 KEYWORD nonn AUTHOR STATUS approved

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

Last modified May 29 04:27 EDT 2020. Contains 334696 sequences. (Running on oeis4.)