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A035324 A convolution triangle of numbers, generalizing Pascal's triangle A007318. 20
1, 3, 1, 10, 6, 1, 35, 29, 9, 1, 126, 130, 57, 12, 1, 462, 562, 312, 94, 15, 1, 1716, 2380, 1578, 608, 140, 18, 1, 6435, 9949, 7599, 3525, 1045, 195, 21, 1, 24310, 41226, 35401, 19044, 6835, 1650, 259, 24, 1, 92378, 169766, 161052, 97954, 40963, 12021, 2450 (list; table; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Replacing each '2' in the recurrence by '1' produces Pascal's triangle A007318(n-1,m-1). The columns appear as A001700, A008549, A045720, A045894, A035330...

Triangle T(n,k), 1<=k<=n, given by (0, 3/1, 1/3, 5/3, 3/5, 7/5, 5/7, 9/7, 7/9, 11/9, 9/11, ...) DELTA (1, 0, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938. - DELEHAM Philippe, Jan 28 2012

Riordan array (1, c(x)/sqrt(1-4x)) where c(x) = g.f. for Catalan numbers A000108, first column (k = 0) omitted . - DELEHAM Philippe, Jan 28 2012

LINKS

W. Lang, On generalizations of Stirling number triangles, J. Integer Seqs., Vol. 3 (2000), #00.2.4.

W. Lang, First 10 rows.

FORMULA

a(n+1, m) = 2*(2*n+m)*a(n, m)/(n+1) + m*a(n, m-1)/(n+1), n >= m >= 1; a(n, m) := 0, n<m; a(n, 0) := 0, a(1, 1)=1; G.f. for column m: ((x*c(x)/sqrt(1-4*x))^m)/x, where c(x) = g.f. for Catalan numbers A000108. a(n, m)=: s2(3; n, m).

With offset 0( 0<=k<=n), T(n,k)=Sum_{j, j>=0}A039598(n,j)*binomial(j,k). - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Mar 30 2007

T(n+1,n) = 3*n = A008585(n).

EXAMPLE

{1}; {3,1}; {10,6,1}; {35,29,9,1};...

Triangle (0,3,1/3,5/3,3/5,...) DELTA (1,0,0,0,0,0, ...) begins :

1

0, 1

0, 3, 1

0, 10, 6, 1

0, 35, 29, 9, 1

0, 126, 130, 57, 12, 1

0, 462, 562, 312, 94, 15, 1

CROSSREFS

Cf. A000108, A007318. Row sums: A049027(n), n >= 1.

If offset 0 (n >= m >= 0): convolution triangle based on A001700 (central binomial coeffs. of odd order).

Alternating row sums give A000108 (Catalan numbers).

Sequence in context: A171509 A171505 A134283 * A171814 A091965 A171568

Adjacent sequences:  A035321 A035322 A035323 * A035325 A035326 A035327

KEYWORD

easy,nice,nonn,tabl

AUTHOR

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)

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Last modified February 16 20:01 EST 2012. Contains 205955 sequences.