|
Search: id:A020918
|
|
|
| A020918 |
|
Expansion of 1/(1-4*x)^(7/2). |
|
+0
8
|
|
| 1, 14, 126, 924, 6006, 36036, 204204, 1108536, 5819814, 29745716, 148728580, 730122120, 3528923580, 16830250920, 79342611480, 370265520240, 1712478031110, 7857252142740, 35794148650260
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
FORMULA
|
a(n)=binomial(n+3, 3)*A000984(n+3)/A000984(3), A000984: central binomial coefficients - from Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)
a(n) ~ 8/15*pi^(-1/2)*n^(5/2)*2^(2*n)*{1 + 35/8*n^-1 + ...} - Joe Keane (jgk(AT)jgk.org), Nov 22 2001
a(n) = sum( a+b+c+d+e+f+g=n, f(a)*f(b)*f(c)*f(d)*f(e)*f(f)*f(g)) with f(n)=A000984(n) . - DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Jan 22 2004
a(n)=A000292(n)*A000984(n+2)/20. - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 05 2007
|
|
MAPLE
|
seq(binomial(2*n, n)*binomial(n, (n-3))/20, n=2..21); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 05 2007
|
|
CROSSREFS
|
Sequence in context: A090296 A088625 A073393 this_sequence A041368 A026882 A166794
Adjacent sequences: A020915 A020916 A020917 this_sequence A020919 A020920 A020921
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com).
|
|
|
Search completed in 0.002 seconds
|
