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A144303
Square array A(n,m), n>=0, m>=0, read by antidiagonals: A(n,m) = n-th number of the m-th iteration of the hyperbinomial transform on the sequence of 1's.
12
1, 1, 1, 1, 2, 1, 1, 3, 6, 1, 1, 4, 13, 29, 1, 1, 5, 22, 81, 212, 1, 1, 6, 33, 163, 689, 2117, 1, 1, 7, 46, 281, 1564, 7553, 26830, 1, 1, 8, 61, 441, 2993, 18679, 101961, 412015, 1, 1, 9, 78, 649, 5156, 38705, 268714, 1639529, 7433032, 1, 1, 10, 97, 911, 8257, 71801, 592489, 4538209, 30640257, 154076201, 1
OFFSET
0,5
COMMENTS
See A088956 for the definition of the hyperbinomial transform.
A(n,m), n>=0, m>=0, is the number of subtrees of the complete graph K_{n+m} on n+m vertices containing a given, fixed subtree on m vertices. - Alex Chin, Jul 25 2013
LINKS
N. J. A. Sloane, Transforms
FORMULA
E.g.f. of column k: exp(x) * (-LambertW(-x)/x)^k.
A(n,k) = Sum_{j=0..n} k * (n-j+k)^(n-j-1) * C(n,j).
EXAMPLE
Square array begins:
1, 1, 1, 1, 1, 1, 1, ...
1, 2, 3, 4, 5, 6, 7, ...
1, 6, 13, 22, 33, 46, 61, ...
1, 29, 81, 163, 281, 441, 649, ...
1, 212, 689, 1564, 2993, 5156, 8257, ...
1, 2117, 7553, 18679, 38705, 71801, 123217, ...
1, 26830, 101961, 268714, 592489, 1166886, 2120545, ...
MAPLE
hymtr:= proc(p) proc(n, m) `if`(m=0, p(n), m*add(
p(k)*binomial(n, k) *(n-k+m)^(n-k-1), k=0..n))
end end:
A:= hymtr(1):
seq(seq(A(n, d-n), n=0..d), d=0..12);
MATHEMATICA
a[_, 0] = 1; a[n_, k_] := Sum[k*(n - j + k)^(n - j - 1)*Binomial[n, j], {j, 0, n}]; Table[a[n - k, k], {n, 0, 10}, {k, n, 0, -1}] // Flatten (* Jean-François Alcover, Jun 24 2013 *)
CROSSREFS
Rows n=0-2 give: A000012, A000027, A028872.
Main diagonal gives A252766.
Sequence in context: A307883 A111528 A363007 * A370072 A287024 A107702
KEYWORD
nonn,tabl
AUTHOR
Alois P. Heinz, Sep 17 2008, revised Oct 30 2012
STATUS
approved