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A026729 Square array of binomial coefficients T(n,k) = binomial(n,k), n >= 0, k >= 0, read by antidiagonals. 24
1, 0, 1, 0, 1, 1, 0, 0, 2, 1, 0, 0, 1, 3, 1, 0, 0, 0, 3, 4, 1, 0, 0, 0, 1, 6, 5, 1, 0, 0, 0, 0, 4, 10, 6, 1, 0, 0, 0, 0, 1, 10, 15, 7, 1, 0, 0, 0, 0, 0, 5, 20, 21, 8, 1, 0, 0, 0, 0, 0, 1, 15, 35, 28, 9, 1, 0, 0, 0, 0, 0, 0, 6, 35, 56, 36, 10, 1, 0, 0, 0, 0, 0, 0, 1, 21, 70, 84, 45, 11, 1, 0, 0, 0, 0 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,9

COMMENTS

The signed triangular matrix T(n,k)*(-1)^(n-k) is the inverse matrix of the triangular Catalan convolution matrix A106566(n,k), n=k>=0, with A106566(n,k) = 0 if n<k . - Philippe DELEHAM Aug 01 2005

As a number triangle : unsigned version of A109466 . [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 26 2008]

A063967*A130595 as infinite lower triangular matrices . [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Dec 11 2008]

Modulo 2, this sequence becomes A106344 . [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Dec 18 2008]

REFERENCES

L. W. Shapiro, S. Getu, W.-J. Woan and L. C. Woodson, The Riordan group, Discrete Applied Math., 34 (1991), 229-239.

FORMULA

As a number triangle, this is defined by : T(n,0) = 0^n, T(0,k) = 0^k, T(n,k) = T(n-1,k-1) + Sum_{j, j>=0} = (-1)^j*T(n-1,k+j)*A000108(j) for n>0 and k>0 . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 07 2005

As a triangle read by rows, it is [0, 1, -1, 0, 0, 0, 0, 0, 0, ...] DELTA [1, 0, 0, 0, 0, 0, 0, 0, ...] where DELTA is the operator defined in A084938 . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 22 2006

As a number triangle, this is defined by T(n, k)=sum{i=0..n, (-1)^(n+i)C(n, i)C(i+k, i-k)} and is the Riordan array ( 1, x/(1+x) ). The row sums of this triangle are F(n+1). - Paul Barry (pbarry(AT)wit.ie), Jun 21 2004

Sum_{k, 0<=k<=n}x^k*T(n,k)= A000007(n), A000045(n+1), A002605(n), A030195(n+1), A057087(n), A057088(n), A057089(n), A057090(n), A057091(n), A057092(n), A057093(n) for n=0,1,2,3,4,5,6,7,8,9,10 . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 16 2006

T(n,k)= A109466(n,k)*(-1)^(n-k). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Dec 11 2008]

EXAMPLE

Array begins

1 0 0 0 0 0 ...

1 1 0 0 0 0 ...

1 2 1 0 0 0 ...

1 3 3 1 0 0 ...

1 4 6 4 1 0 ...

As a triangle, this begins

1

0 1

0 1 1

0 0 2 1

0 0 1 3 1

0 0 0 3 4 1

0 0 0 1 6 5 1

...

CROSSREFS

The official entry for Pascal's triangle is A007318. See also A052553.

Cf. A030528 (subtriangle for 1<=k<=n).

Sequence in context: A108063 A164846 * A109466 A076833 A071676 A115363

Adjacent sequences:  A026726 A026727 A026728 * A026730 A026731 A026732

KEYWORD

nonn,tabl,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Jan 19 2003

EXTENSIONS

More terms from Benoit Cloitre (benoit7848c(AT)orange.fr), Jan 19 2003

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Last modified February 17 10:05 EST 2012. Contains 206009 sequences.