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A104259 Triangle T read by rows: matrix product of Pascal and Catalan triangle. 8
1, 2, 1, 5, 4, 1, 15, 14, 6, 1, 51, 50, 27, 8, 1, 188, 187, 113, 44, 10, 1, 731, 730, 468, 212, 65, 12, 1, 2950, 2949, 1956, 970, 355, 90, 14, 1, 12235, 12234, 8291, 4356, 1785, 550, 119, 16, 1, 51822, 51821, 35643, 19474, 8612, 3021, 805, 152, 18, 1 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Also, Riordan array (G,G), G(t)=(1 - ((1-5*t)/(1-t))^(1/2))/(2*t).

From Emanuele Munarini, May 18 2011: (Start)

Row sums = A002212.

Diagonal sums = A190737.

Central coefficients = A190738. (End)

LINKS

D. Merlini, R. Sprugnoli and M. C. Verri, An algebra for proper generating trees

FORMULA

T(n,k) = sum(binomial(n,i)*binomial(2*i-k,i-k)*(k+1)/(i+1),i=k..n).

T(n+1,k+2) = T(n+1,k+1) + T(n,k+2) - T(n,k+1) - T(n,k). [Emanuele Munarini, May 18 2011]

EXAMPLE

Triangle begins:

1

2, 1

5, 4, 1

15, 14, 6, 1

51, 50, 27, 8, 1

188, 187, 113, 44, 10, 1

731, 730, 468, 212, 65, 12, 1

2950, 2949, 1956, 970, 355, 90, 14, 1

12235, 12234, 8291, 4356, 1785, 550, 119, 16, 1

MATHEMATICA

Flatten[Table[Sum[Binomial[n, i]Binomial[2i-k, i-k](k+1)/(i+1), {i, k, n}], {n, 0, 100}, {k, 0, n}]] [Emanuele Munarini, May 18 2011]

PROG

(Maxima) create_list(sum(binomial(n, i)*binomial(2*i-k, i-k)*(k+1)/(i+1), i, k, n), n, 0, 12, k, 0, n); [Emanuele Munarini, May 18 2011]

CROSSREFS

T = A007318 * A033184.

Left-hand columns include A007317, A007317 - 1. Row sums are in A002212.

Sequence in context: A193673 A126181 A154930 * A137650 A171515 A110271

Adjacent sequences:  A104256 A104257 A104258 * A104260 A104261 A104262

KEYWORD

nonn,tabl

AUTHOR

Ralf Stephan, Mar 17 2005

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Last modified February 14 11:36 EST 2012. Contains 205623 sequences.