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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A132303 Sum of cubes of trinomial coefficients: a(n) = Sum_{k=0..2n} trinomial(n,k)^3 where trinomial(n,k) = [x^k] (1 + x + x^2)^n. 4
1, 3, 45, 831, 17181, 375903, 8530929, 198643455, 4714491357, 113550338127, 2767105469745, 68077260387315, 1688160321677025, 42142679453321307, 1058050429855640217, 26695057057648257231, 676431705046728704733 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..16.

PROG

(PARI) a(n)=sum(k=0, 2*n, polcoeff((1+x+x^2)^n, k)^3)

CROSSREFS

Cf. A132304, A132305.

Sequence in context: A287031 A124487 A266698 * A298799 A202437 A008931

Adjacent sequences:  A132300 A132301 A132302 * A132304 A132305 A132306

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Aug 18 2007

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 April 24 16:26 EDT 2019. Contains 322430 sequences. (Running on oeis4.)