|
Search: id:A091526
|
|
|
| A091526 |
|
Coefficient of x^n in 1/((1+x)(1-x)^(n-1)). |
|
+0
2
|
|
| 1, -1, 1, 2, 9, 34, 130, 496, 1897, 7274, 27966, 107788, 416394, 1611908, 6251596, 24287212, 94499689, 368202778, 1436458486, 5610483532, 21936442894, 85852554748, 336300861436, 1318441228432, 5172792817834, 20309402206084
(list; graph; listen)
|
|
|
OFFSET
|
0,4
|
|
|
COMMENT
|
Number of positive terms in expansion of (x_1+x_2+...+x_{n-1}-x_n)^(n+1). - Sergio Falcon (sfalcon(AT)dma.ulpgc.es), Feb 08 2007
|
|
PROGRAM
|
(PARI) a(n)=sum(i=0, n, binomial(n+i-2, i)*(-1)^(n-i))
|
|
CROSSREFS
|
Sequence in context: A120989 A010763 A077234 this_sequence A150937 A150938 A151307
Adjacent sequences: A091523 A091524 A091525 this_sequence A091527 A091528 A091529
|
|
KEYWORD
|
sign
|
|
AUTHOR
|
Michael Somos, Jan 18 2004
|
|
|
Search completed in 0.002 seconds
|
