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A117389 A skew Delannoy number triangle read by rows. +0
1
1, 0, 1, 0, 1, 1, 0, 0, 3, 1, 0, 0, 1, 5, 1, 0, 0, 0, 5, 7, 1, 0, 0, 0, 1, 13, 9, 1, 0, 0, 0, 0, 7, 25, 11, 1, 0, 0, 0, 0, 1, 25, 41, 13, 1, 0, 0, 0, 0, 0, 9, 63, 61, 15, 1, 0, 0, 0, 0, 0, 1, 41, 129, 85, 17, 1 (list; table; graph; listen)
OFFSET

0,9

COMMENT

Row sums are the trinomial numbers A000073(n+2). Diagonal sums are A079973.

FORMULA

Number triangle T(n,k)=[k<=n]*sum{j=0..2k-n, C(2k-n,j)C(n-k,j)2^j}; T(n,k)=sum{j=0..2k-n, C(2k-n,j)C(n-k,n-k-j)2^j};

EXAMPLE

Triangle begins

1,

0, 1,

0, 1, 1,

0, 0, 3, 1,

0, 0, 1, 5, 1,

0, 0, 0, 5, 7, 1,

0, 0, 0, 1, 13, 9, 1,

0, 0, 0, 0, 7, 25, 11, 1

CROSSREFS

Cf. A008288.

Adjacent sequences: A117386 A117387 A117388 this_sequence A117390 A117391 A117392

Sequence in context: A128208 A094544 A062734 this_sequence A122083 A098158 A110319

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Mar 11 2006

page 1

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Last modified October 13 17:46 EDT 2008. Contains 145008 sequences.


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