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A094305 Triangle read by rows: T(n,k) = (n+1)(n+2)/2 * binomial(n,k) (0 <= k <= n). 6
1, 3, 3, 6, 12, 6, 10, 30, 30, 10, 15, 60, 90, 60, 15, 21, 105, 210, 210, 105, 21, 28, 168, 420, 560, 420, 168, 28, 36, 252, 756, 1260, 1260, 756, 252, 36, 45, 360, 1260, 2520, 3150, 2520, 1260, 360, 45, 55, 495, 1980, 4620, 6930, 6930, 4620, 1980, 495, 55, 66 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Sum of all possible sums of k numbers chosen from among the first n+1 numbers. Additive analogue of triangle of Stirling numbers of first kind (A008275).

Third slice along the 1-2-plane in the cube a(m,n,o) = a(m-1,n,o)+a(m,n-1,o)+a(m,n,o-1) with a(1,0,0)=1 and a(m<>1=0,n>=0,0>=o)=0, for which the first slice is Pascal's triangle (slice read by anti-diagonals). - Thomas Wieder (thomas.wieder(AT)t-online.de), Aug 06 2006

Sum of all possible sums of k+1 numbers chosen from among the first n+1 numbers. Additive analogue of triangle of Stirling numbers of first kind (A008275). - David Wasserman (dwasserm(AT)earthlink.net), Oct 04 2007

Triangle T(n,k), 0<=k<=n, read by rows given by [3,-1,2/3,-1/6,1/2,0,0,0,0,0,0,...] DELTA [3,-1,2/3,-1/6,1/2,0,0,0,0,0,0,...] where DELTA is the operator defined in A084938 . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 07 2007

REFERENCES

A. T. Benjamin and J. J. Quinn, Proofs that really count: the art of combinatorial proof, M.A.A. 2003, identity 152.

EXAMPLE

Triangle begins:

1

3 3

6 12 6

10 30 30 10

15 60 90 60 15

21 105 210 210 105 21

...

The n-th row is the product of the n-th triangular number and the n-th row of Pascal's triangle. The fifth row is (15,60,90,60,15) or 15*{1,4,6,4,1}.

MAPLE

T:= proc(n, k) (n+1)*(n+2)/2 * binomial(n, k); end;

CROSSREFS

Columns include A000217. Row sums are A001788. Cf. A094306.

Cf. A003506, A121547, A121306, A119800, A000217, A007318.

Sequence in context: A169944 A110952 A025250 * A057963 A112434 A050067

Adjacent sequences:  A094302 A094303 A094304 * A094306 A094307 A094308

KEYWORD

nonn,tabl,easy

AUTHOR

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Apr 29 2004

EXTENSIONS

Edited by Ralf Stephan, Feb 04 2005. Further comments from David Wasserman (dwasserm(AT)earthlink.net), Oct 04 2007

Further editing by N. J. A. Sloane (njas(AT)research.att.com), Oct 07 2007

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Last modified February 16 14:37 EST 2012. Contains 205930 sequences.