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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A227469 a(n) = binomial((n+1)^2, n) * (2*n+1) / (n+1)^2 for n>=0. 0
1, 3, 20, 245, 4554, 115192, 3709992, 145597545, 6750522350, 361424043596, 21958844607336, 1493260499980119, 112400273159533800, 9279595605913516080, 833858283261973732944, 81027308003810095983825, 8466793463341565312119830, 946776552967215128481968260, 112816032067073649248569919400 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..18.

FORMULA

a(n) = (2*n+1)*A143669(n).

EXAMPLE

G.f.: A(x) = 1 + 3*x + 20*x^2 + 245*x^3 + 4554*x^4 + 115192*x^5 +...

PROG

(PARI) {a(n)=binomial((n+1)^2, n)*(2*n+1)/(n+1)^2}

for(n=0, 20, print1(a(n), ", "))

CROSSREFS

Cf. A143669.

Sequence in context: A237431 A237652 A256018 * A262208 A324955 A183607

Adjacent sequences:  A227466 A227467 A227468 * A227470 A227471 A227472

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Aug 23 2013

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 October 17 16:51 EDT 2019. Contains 328120 sequences. (Running on oeis4.)