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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A079590 C(6n+1,n). 2
1, 7, 78, 969, 12650, 169911, 2324784, 32224114, 450978066, 6358402050, 90177170226, 1285063345176, 18385569737808, 263926640438545, 3799541229226200, 54834293825867556, 793067310934426018 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(n) is the number of paths from (0,0) to (6n,n) taking north and east steps and avoiding north^{=2}. - Shanzhen Gao, Apr 15 2010

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

FORMULA

a(n) is asymptotic to c*sqrt(n)*(46656/3125)^n with c= 0.5243... [c = 2*3^(3/2)/(5^(3/2)*sqrt(Pi)) = 0.52442324668419795386... - Vaclav Kotesovec, Feb 14 2019]

G.f.: hypergeom([1/3, 1/2, 2/3, 5/6, 7/6], [2/5, 3/5, 4/5, 6/5], (46656/3125)*x). - Robert Israel, Aug 07 2014

MAPLE

seq(binomial(6*n+1, n), n = 1 .. 100); # Robert Israel, Aug 07 2014

MATHEMATICA

Table[Binomial[6 n + 1, n], {n, 0, 20}] (* Vincenzo Librandi, Aug 07 2014 *)

PROG

(MAGMA) [Binomial(6*n+1, n): n in [0..20]]; // Vincenzo Librandi, Aug 07 2014

CROSSREFS

Cf. A052203.

Sequence in context: A210406 A133272 A186657 * A202755 A280518 A156714

Adjacent sequences:  A079587 A079588 A079589 * A079591 A079592 A079593

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Jan 26 2003

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 23 20:42 EDT 2021. Contains 347617 sequences. (Running on oeis4.)