|
| |
|
|
A072976
|
|
a(n)=2^n*binomial(3*n,n)*(3*n+2).
|
|
1
| |
|
|
2, 30, 480, 7392, 110880, 1633632, 23761920, 342328320, 4895294976, 69589977600, 984515051520, 13872712089600, 194821130649600, 2728095278727168, 38106727702855680, 531128942672216064
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,1
|
|
|
LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..100
|
|
|
FORMULA
| sum(k>=0, 1/a(k) ) = ( 7*Pi -24*Log(2) )/10 = 0.53556162416898...
|
|
|
MATHEMATICA
| Table[2^n Binomial[3n, n](3n+2), {n, 0, 20}] (* From Harvey P. Dale, Aug 20 2011 *)
|
|
|
PROG
| (PARI) a(n)=2^n*binomial(3*n, n)*(3*n+2)
(MAGMA) [2^n*Binomial(3*n, n)*(3*n+2): n in [0..20]]; // Vincenzo Librandi, Aug 20 2011
|
|
|
CROSSREFS
| Sequence in context: A077517 A060042 A134362 * A143414 A099046 A020547
Adjacent sequences: A072973 A072974 A072975 * A072977 A072978 A072979
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Benoit Cloitre (benoit7848c(AT)orange.fr), Aug 13 2002
|
|
|
EXTENSIONS
| Corrected a(1) by Harvey P. Dale, Aug 20 2011
|
| |
|
|
