login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A188478 Binomial variation of the Catalan numbers 2
1, 1, 1, 2, 4, 11, 33, 116, 456, 1999, 9623, 50603, 288287, 1769352, 11636669, 81652911, 608857325, 4807873069, 40080193414, 351751992542, 3241754135966, 31301851579056, 316012152140592, 3329322705562603, 36539984716325869, 417102552119591395, 4944630222121834001, 60791493200390178470 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
LINKS
FORMULA
a(n) = sum( binomial(n-1-i, i)*a(i)*a(n-1-i), i=0..(n-1) ) with a(0)=1
MATHEMATICA
a[0] = 1; a[n_] := a[n] = Sum[ Binomial[n - i - 1, i] a[i]*a[n - 1 - i], {i, 0, n - 1}]; Table[a[i], {i, 0, 30}]
CROSSREFS
Sequence in context: A268320 A127782 A002846 * A302547 A123444 A123473
KEYWORD
nonn,easy
AUTHOR
Olivier Gérard, Apr 01 2011
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 20 12:36 EDT 2024. Contains 371844 sequences. (Running on oeis4.)