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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A179432 a(n) = C(2*3^(n-1), n). 4
1, 2, 15, 816, 316251, 873642672, 17743125256857, 2739097835911193328, 3301626910467952067341626, 31698997711344336177849363574320, 2460103385023594223069956382123378560008 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Equals column 0 in the matrix square of triangle T=A179430 where column 0 of T^m equals C(m*3^(n-1), n) at row n for n>=0, m>=0.

LINKS

Table of n, a(n) for n=0..10.

FORMULA

G.f.: A(x) = Sum_{n>=0} (2/3)^n * log(1 + 3^n*x)^n / n!.

a(n) ~ 2^n * 3^(n*(n-1)) / n!. - Vaclav Kotesovec, Jul 02 2016

EXAMPLE

G.f.: A(x) = 1 + 2*x + 15*x^2 + 816*x^3 + 316251*x^4 +...

A(x) = 1 + 2*log(1+3*x)/3 + 2^2*log(1+3^2*x)^2/(3^2*2!) + 2^3*log(1+3^3*x)^3/(3^3*3!) + 2^4*log(1+3^4*x)^4/(3^4*4!) +...

MATHEMATICA

Table[Binomial[2*3^(n-1), n], {n, 0, 15}] (* Vaclav Kotesovec, Jul 02 2016 *)

PROG

(PARI) {a(n)=binomial(2*3^(n-1), n)}

(PARI) /* G.f. A(x) as Sum of Series: */

{a(n)=polcoeff(sum(k=0, n, (2/3)^k*log(1+3^k*x +x*O(x^n))^k/k!), n)}

CROSSREFS

Cf. A179430, A179431, A136393, A179433, A179434.

Sequence in context: A038017 A012993 A216331 * A007542 A090604 A007467

Adjacent sequences:  A179429 A179430 A179431 * A179433 A179434 A179435

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Jul 20 2010

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 May 19 07:05 EDT 2019. Contains 323386 sequences. (Running on oeis4.)