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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A129275 Column 1 of triangle A129274; a(n) is the coefficient of q^(n+2) in the squared q-factorial of n+2. 1
1, 10, 71, 474, 3103, 20190, 131204, 853176, 5555674, 36237258, 236763125, 1549496420, 10156512792, 66669881442, 438226458380, 2884072387268, 19002479773355, 125335000366692, 827479642104143, 5468060901435850 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..19.

Eric Weisstein's World of Mathematics, q-Factorial from MathWorld.

FORMULA

a(n) = [q^(n+2)] Product_{i=1..n+2} { (1-q^i)/(1-q) }^2.

PROG

(PARI) a(n)=polcoeff(prod(i=1, n+2, (1-x^i)/(1-x))^2, n+2)

CROSSREFS

Cf. A129274.

Sequence in context: A026772 A224292 A016098 * A049672 A221548 A037579

Adjacent sequences:  A129272 A129273 A129274 * A129276 A129277 A129278

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Apr 07 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified February 19 20:48 EST 2018. Contains 299357 sequences. (Running on oeis4.)