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A080251 Paired decomposition of tetrahedral numbers A000292 arranged as number triangle. 2
1, 2, 2, 3, 3, 4, 4, 4, 6, 6, 5, 5, 8, 8, 9, 6, 6, 10, 10, 12, 12, 7, 7, 12, 12, 15, 15, 16, 8, 8, 14, 14, 18, 18, 20, 20, 9, 9, 16, 16, 21, 21, 24, 24, 25, 10, 10, 18, 18, 24, 24, 28, 28, 30, 30, 11, 11, 20, 20, 27, 27, 32, 32, 35, 35, 36 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Used in construction of Stirling-like number triangle A080416.

REFERENCES

R. B. Corcino, K. J. M. Gonzales, M. J. C. Loquias and E. L. Tan, Dually weighted Stirling-type sequences, arXiv preprint arXiv:1302.4694, 2013

LINKS

Table of n, a(n) for n=0..65.

FORMULA

T(n,k)=[k<=n]*floor((k+2)/2)*(n-k+floor((k+3)/2)). [From Paul Barry, Jun 14 2010]

Also generated by the product of pairs of integers 0<=r1,r2<=n whose sum is n+2

EXAMPLE

Rows are {1}, {2,2}, {3,3,4}, {4,4,6,6}, {5,5,8,8,9}, ... Row sums are 1, 4, 10, 20, .... or C(n+3,3)=A000292.

CROSSREFS

Sequence in context: A103358 A063084 A127079 * A220032 A219773 A187446

Adjacent sequences:  A080248 A080249 A080250 * A080252 A080253 A080254

KEYWORD

nonn,tabl

AUTHOR

Paul Barry, Feb 17 2003

EXTENSIONS

Edited by Ken Joffaniel M Gonzales, Jul 04 2010

STATUS

approved

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Last modified May 26 04:23 EDT 2013. Contains 225653 sequences.