Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A126985
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A126985 Expansion of 1/(1+8*x*c(x)), c(x) the g.f. of Catalan numbers A000108. +0
5
1, -8, 56, -400, 2840, -20208, 143664, -1021728, 7265240, -51665200, 367392656, -2612584928, 18578329456, -132112749920, 939467783520, -6680662171200, 47506922377560, -337827035002800, 2402325467002320, -17083203745473120, 121480558396908240, -863861754435010080 (list; graph; listen)
OFFSET

0,2

COMMENT

Hankel transform is (-8)^n.

FORMULA

a(n)=Sum_{k, 0<=k<=n}A039599(n,k)*(-9)^k.

MAPLE

c:=(1-sqrt(1-4*x))/2/x: ser:=series(1/(1+8*x*c), x=0, 25): seq(coeff(ser, x, n), n=0..21); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 24 2007

CROSSREFS

Sequence in context: A063812 A003950 A033134 this_sequence A027081 A093134 A001398

Adjacent sequences: A126982 A126983 A126984 this_sequence A126986 A126987 A126988

KEYWORD

sign

AUTHOR

Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Mar 21 2007

EXTENSIONS

More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 24 2007

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified July 26 13:41 EDT 2008. Contains 142293 sequences.


AT&T Labs Research