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A065077 Triangle read by rows: T(n,m) = C[n,m,m] where C[i,j,k] is the 3-dimensional Catalan pyramid defined by C[0,0,0]=1 and C[i,j,k]=0 if j>i or k>j and C[i,j,k]=C[i-1,j,k]+C[i,j-1,k]+C[i,j,k-1]. +0
1
1, 1, 1, 1, 3, 5, 1, 6, 21, 42, 1, 10, 56, 210, 462, 1, 15, 120, 660, 2574, 6006, 1, 21, 225, 1650, 9009, 36036, 87516, 1, 28, 385, 3575, 25025, 136136, 554268, 1385670, 1, 36, 616, 7007, 60060, 408408, 2217072, 9145422, 23371634, 1, 45, 936, 12740, 129948 (list; table; graph; listen)
OFFSET

0,5

COMMENT

T(n,m)= number of standard tableaux of shape (n,m,m) (0<m<=n). - Emeric Deutsch (deutsch(AT)duke.poly.edu), May 14 2004

FORMULA

C[0, 0, 0] := 1; C[x_, y_, z_] := 0 /; (x< y || y< z); C[u_, v_, 0] := (u+v)!/(u+1)!/(v)!(u-v+1); C[_, 0, 0] := 1; C[x_, y_, z_] := (C[x, y, z]= C[x-1, y, z]+C[x, y-1, z] +C[x, y, z-1]) /; (y<=x ||z<=y); Table[C[x, y, y], {x, 0, 10}, {y, 0, x}]

T(n, m)=(n+2m)!(n-m+1)(n-m+2)/[m!(m+1)!(n+2)! ] (0<=m<=n). - Emeric Deutsch (deutsch(AT)duke.poly.edu), May 14 2004

EXAMPLE

1; 1,1; 1,3,5; 1,6,21,42; 1,10,56,210,462; 1,15,120,660,2574,6006; ...

T(2,1)=3 because in the first row of the diagram (2,1,1) we can have 12 or 13 or 14.

MAPLE

a:=proc(n, m) if m<=n then (n+2*m)!*(n-m+1)*(n-m+2)/m!/(m+1)!/(n+2)! else 0 fi end: seq(seq(a(n, m), m=0..n), n=0..9);

CROSSREFS

Last number in each row is A005789

Cf. A005789, A065058, A065078.

Sequence in context: A076553 A061649 A073365 this_sequence A118788 A028510 A122053

Adjacent sequences: A065074 A065075 A065076 this_sequence A065078 A065079 A065080

KEYWORD

nonn,tabl

AUTHOR

Wouter Meeussen (wouter.meeussen(AT)pandora.be), Nov 09 2001

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


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