login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A114449 If H(0,n) = 1/n, H(m,n) = sum{k=1...n} H(m-1,k), then a(n) = (2n)!*H(n,2n)/(4n-1). 1
1, 22, 2232, 526256, 223342560, 149004576000, 143638792012800, 188865721926604800, 324805825447366348800, 707653302810219988992000, 1904745046396912124461056000, 6206775274489558456631623680000 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Every term is an integer.

EXAMPLE

H(2,4) = H(1,1) +H(1,2) +H(1,3) +H(1,4) =

1 + (1 +1/2) + (1 +1/2 +1/3) + (1 +1/2 + 1/3 +1/4) = 77/12.

So a(2) = 24 *(77/12)/7 = 22.

MAPLE

H := proc(m, n) option remember ; if m = 0 then 1/n ; else add( H(m-1, k), k=1..n) ; fi ; end: A114449 := proc(n) (2*n)!*H(n, 2*n)/(4*n-1) ; end: for n from 1 to 20 do printf("%d, ", A114449(n)) ; od: - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 30 2008

CROSSREFS

Sequence in context: A183488 A046445 A133235 * A069221 A069222 A117990

Adjacent sequences:  A114446 A114447 A114448 * A114450 A114451 A114452

KEYWORD

nonn

AUTHOR

Leroy Quet Feb 14 2006

EXTENSIONS

More terms from Brent A. Yorgey (byorgey(AT)gmail.com), Jul 27 2007

More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 30 2008

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 13 14:15 EST 2012. Contains 205503 sequences.