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A122542 Triangle T(n,k), 0<=k<=n, read by rows, given by [0, 2, -1, 0, 0, 0, 0, 0, ...] DELTA [1, 0, 0, 0, 0, 0, 0, 0, ...] where DELTA is the oprator defined in A084938. 11
1, 0, 1, 0, 2, 1, 0, 2, 4, 1, 0, 2, 8, 6, 1, 0, 2, 12, 18, 8, 1, 0, 2, 16, 38, 32, 10, 1, 0, 2, 20, 66, 88, 50, 12, 1, 0, 2, 24, 102, 192, 170, 72, 14, 1, 0, 2, 28, 146, 360, 450, 292, 98, 16, 1, 0, 2, 32, 198, 608, 1002, 912, 462, 128, 18, 1 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,5

COMMENTS

Riordan array (1, x*(1+x)/(1-x)) . Rising and falling diagonals are the tribonacci numbers A000213, A001590.

FORMULA

Sum_{k, 0<=k<=n}x^k*T(n,k) = A000007(n), A001333(n), A104934(n), A122558(n), A122690(n), A091928(n)  for x = 0, 1, 2, 3, 4, 5 . DELEHAM Philippe, Jan 25 2012 .

Sum_{k, 0<=k<=n}3^(n-k)*T(n,k) = A086901(n).

Sum_{k, 0<=k<=n}2^(n-k)*T(n,k)=A007483(n-1), n>=1 . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 08 2006

T(2*n,n)=A123164(n).

T(n,k) = T(n-1,k) + T(n-1,k-1) + T(n-2,k-1), n>1. - DELEHAM Philippe, Jan 25 2012

EXAMPLE

Triangle begins:

1;

0, 1;

0, 2, 1;

0, 2, 4, 1;

0, 2, 8, 6, 1;

0, 2, 12, 18, 8, 1;

0, 2, 16, 38, 32, 10, 1;

0, 2, 20, 66, 88, 50, 12, 1;

0, 2, 24, 102, 192, 170, 72, 14, 1;

0, 2, 28, 146, 360, 450, 292, 98, 16, 1;

0, 2, 32, 198, 608, 1002, 912, 462, 128, 18, 1;

CROSSREFS

Cf. A113413, A035607. Diagonals : A000012, A005843, A001105, A035597-A035606. Columns : A000007, A040000, A008575, A005899, A008412-A008416, A008418, A008420, A035706-A035745.

Sequence in context: A206022 A115247 A204163 * A098542 A141343 A066709

Adjacent sequences:  A122539 A122540 A122541 * A122543 A122544 A122545

KEYWORD

nonn,tabl

AUTHOR

Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Sep 19 2006, May 28 2007

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Last modified February 17 11:46 EST 2012. Contains 206011 sequences.