|
Search: id:A123335
|
|
|
| A123335 |
|
a(0)=1, a(1)=-1, a(n)=-2*a(n-1)+a(n-2)for n>1 . |
|
+0
2
|
|
| 1, -1, 3, -7, 17, -41, 99, -239, 577, -1393, 3363, -8119, 19601, -47321, 114243, -275807, 665857, -1607521, 3880899, -9369319, 22619537, -54608393, 131836323, -318281039, 768398401, -1855077841, 4478554083, -10812186007, 26102926097, -63018038201, 152139002499
(list; graph; listen)
|
|
|
OFFSET
|
0,3
|
|
|
COMMENT
|
Inverse binomial transform of A077957 .
|
|
FORMULA
|
a(n)=(-1)^n*A001333(n). G.f.:(1+x)/(1+2*x-x^2).
a(n)=1/2*{[ -1-sqrt(2)]^n+[ -1+sqrt(2)]^n}, with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Nov 19 2008]
|
|
CROSSREFS
|
Sequence in context: A089737 A001333 A078057 this_sequence A089742 A131721 A058351
Adjacent sequences: A123332 A123333 A123334 this_sequence A123336 A123337 A123338
|
|
KEYWORD
|
easy,sign
|
|
AUTHOR
|
Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jun 27 2007
|
|
EXTENSIONS
|
Corrected by N. J. A. Sloane (njas(AT)research.att.com), Oct 05 2008
|
|
|
Search completed in 0.002 seconds
|
