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A080251
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Paired decomposition of tetrahedral numbers A000292 arranged as number triangle.
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2
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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; internal format)
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OFFSET
| 0,2
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COMMENTS
| Used in construction of Stirling-like number triangle A080416.
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FORMULA
| T(n,k)=[k<=n]*floor((k+2)/2)*(n-k+floor((k+3)/2)). [From Paul Barry (pbarry(AT)wit.ie), Jun 14 2010]
Also generated by the product of pairs of integers 0<=r1,r2<=n whose sum is n+2
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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.
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CROSSREFS
| Sequence in context: A103358 A063084 A127079 * A187446 A167232 A137791
Adjacent sequences: A080248 A080249 A080250 * A080252 A080253 A080254
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KEYWORD
| nonn,tabl
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AUTHOR
| Paul Barry (pbarry(AT)wit.ie), Feb 17 2003
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EXTENSIONS
| Edited by Ken Joffaniel Gonzales (kenjo_kenjo(AT)yahoo.com), Jul 04 2010
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