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A080416 Stirling-like number triangle defined by paired decomposition of C(n+3,3) = A000292. +0
2
1, 1, 1, 1, 4, 1, 1, 12, 10, 1, 1, 32, 67, 20, 1, 1, 80, 376, 252, 35, 1, 1, 192, 1909, 2560, 742, 56, 1, 1, 448, 9094, 22928, 12346, 1848, 84, 1, 1, 1024, 41479, 189120, 177599, 46912, 4074, 120, 1, 1, 2304, 183412, 1472704, 2318149 (list; table; graph; listen)
OFFSET

0,5

COMMENT

Note that the Stirling numbers of the second kind are generated in a similar fashion by decomposing the triangular numbers C(n+2,2) as {1}, {1,2}, {1,2,3} .... The defining sequence A000292 appears as the sub-diagonal when the triangle is arranged in lower-triangular form. The second column is A001787.

FORMULA

Columns are generated as follows : Display C(n+3, 3) as row sums of the triangle A080251, or {1}, {2, 2}, {3, 3, 4}, {4, 4, 6, 6}, {5, 5, 8, 8, 9}, ... The columns are then generated by 1/(1-x), 1/(1-2x)^2, 1/(1-3x)^2(1-4x)), 1/((1-4x)^2(1-6x)^2)) etc

EXAMPLE

Rows are {1}, {1,1}, {1,4,1}, {1,12,10,1}, {1,32,67,20,1},...

CROSSREFS

Cf. A080251, A000292, A008277, A001787.

Adjacent sequences: A080413 A080414 A080415 this_sequence A080417 A080418 A080419

Sequence in context: A008292 A101919 A055106 this_sequence A099759 A072590 A111636

KEYWORD

easy,nonn,tabl

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Feb 17 2003

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Last modified May 12 17:05 EDT 2008. Contains 139661 sequences.


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