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 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; text; internal format)
 OFFSET 1,2 COMMENTS Every term is an integer. LINKS 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, Jan 30 2008 CROSSREFS Sequence in context: A253128 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, Jul 27 2007 More terms from R. J. Mathar, Jan 30 2008 STATUS approved

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Last modified October 23 21:57 EDT 2019. Contains 328373 sequences. (Running on oeis4.)