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A154233 A recursive triangular sequence: A(n,k)= A(n - 1, k - 1) + A(n - 1, k) +(n^2 - n - 1)*A(n - 2, k - 1). 0
1, 1, 1, 1, 7, 1, 1, 19, 19, 1, 1, 39, 171, 39, 1, 1, 69, 761, 761, 69, 1, 1, 111, 2429, 8533, 2429, 111, 1, 1, 167, 6335, 52817, 52817, 6335, 167, 1, 1, 239, 14383, 231611, 711477, 231611, 14383, 239, 1, 1, 329, 29485, 809809, 5643801, 5643801, 809809, 29485, 329 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

Row sums are:

{1, 2, 9, 40, 251, 1662, 13615, 118640, 1203945, 12966850,...}.

LINKS

Table of n, a(n) for n=0..53.

FORMULA

A(n,k)= A(n - 1, k - 1) + A(n - 1, k) +(n^2 - n - 1)*A(n - 2, k - 1).

EXAMPLE

{1},

{1, 1},

{1, 7, 1},

{1, 19, 19, 1},

{1, 39, 171, 39, 1},

{1, 69, 761, 761, 69, 1},

{1, 111, 2429, 8533, 2429, 111, 1},

{1, 167, 6335, 52817, 52817, 6335, 167, 1},

{1, 239, 14383, 231611, 711477, 231611, 14383, 239, 1},

{1, 329, 29485, 809809, 5643801, 5643801, 809809, 29485, 329, 1}

MATHEMATICA

A[n_, 1] := 1; A[n_, n_] := 1;

A[n_, k_] := A[n - 1, k - 1] + A[n - 1, k] + (n^2 - n - 1)*A[n - 2, k - 1];

Table[Table[A[n, m], {m, 1, n}], {n, 1, 10}];

Flatten[%]

CROSSREFS

Sequence in context: A141597 A176561 A176284 * A174033 A119727 A157272

Adjacent sequences:  A154230 A154231 A154232 * A154234 A154235 A154236

KEYWORD

nonn,uned,tabl

AUTHOR

Roger L. Bagula, Jan 05 2009

STATUS

approved

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Last modified May 31 13:01 EDT 2020. Contains 334748 sequences. (Running on oeis4.)