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A127648 Triangle read by rows: row n consists of n zeros followed by n+1. 36
1, 0, 2, 0, 0, 3, 0, 0, 0, 4, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 7, 0, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 13, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 15 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

Alternatively, a(n) = k if n is the k-th triangular number and 0 otherwise.

Triangle T(n,k), 0<=k<=n, read by rows, given by (0,0,0,0,0,0,0,0,0,0,...) DELTA (2,-1/2,1/2,0,0,0,0,0,0,0,...)where DELTA is the operator defined in A084938. - From DELEHAM Philippe, Oct 27 2011

FORMULA

Infinite lower triangular matrix with (1, 2, 3,...) in the main diagonal and the rest zeros.

EXAMPLE

First few rows of the triangle are:

1;

0, 2;

0, 0, 3;

0, 0, 0, 4;

0, 0, 0, 0, 5;

0, 0, 0, 0, 0, 6;

0, 0, 0, 0, 0, 0, 7;

...

MATHEMATICA

Flatten[Table[{n, Table[0, {n}]}, {n, 15}]] (* From Harvey P. Dale, Jul 27 2011 *)

CROSSREFS

This sequence * A007318 (Pascal's Triangle) = A003506 with row sums A001787; A007318 * this sequence = A103406 with row sums A001792.

Cf. A007318, A003506, A001787, A103406, A001792, A084938

Sequence in context: A019263 A169776 A091731 * A132681 A132825 A049597

Adjacent sequences:  A127645 A127646 A127647 * A127649 A127650 A127651

KEYWORD

nonn,easy,tabl

AUTHOR

Gary W. Adamson (qntmpkt(AT)yahoo.com), Jan 22 2007

EXTENSIONS

More terms from Terryjames Morris (trm5002(AT)psu.edu), Mar 09 2007

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Last modified February 14 22:50 EST 2012. Contains 205684 sequences.