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A162610
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Triangle read by rows in which row n lists n terms, starting with 2n-1, with gaps = n-1 between successive terms.
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12
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1, 3, 4, 5, 7, 9, 7, 10, 13, 16, 9, 13, 17, 21, 25, 11, 16, 21, 26, 31, 36, 13, 19, 25, 31, 37, 43, 49, 15, 22, 29, 36, 43, 50, 57, 64, 17, 25, 33, 41, 49, 57, 65, 73, 81, 19, 28, 37, 46, 55, 64, 73, 82, 91, 100, 21, 31, 41, 51, 61, 71, 81, 91, 101, 111, 121
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Note that the last term of the n-th row is the n-th square A000290(n).
Row sums are n*(n^2+2*n-1)/2, apparently in A127736. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 20 2009]
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LINKS
| Harvey P. Dale, Table of n, a(n) for n = 1..10000
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FORMULA
| T(n,k) = n+k*n-k, 1<=k<=n. [From R. J. Mathar, Oct 20 2009]
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EXAMPLE
| Triangle begins:
1
3, 4
5, 7, 9
7, 10, 13, 16
9, 13, 17, 21, 25
11, 16, 21, 26, 31, 36
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MATHEMATICA
| Flatten[Table[NestList[#+n-1&, 2n-1, n-1], {n, 15}]] (* From Harvey P. Dale, Oct 20 2011 *)
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PROG
| Contribution from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 20 2009: (Start)
(Python) def A162610(n, k):
...return 2*n-1+(k-1)*(n-1)
print([A162610(n, k) for n in range(1, 20) for k in range(1, n+1)])
(End)
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CROSSREFS
| Cf. A000027, A000290, A159797, A159798.
Sequence in context: A174269 A112882 A180152 * A155935 A081606 A079945
Adjacent sequences: A162607 A162608 A162609 * A162611 A162612 A162613
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KEYWORD
| easy,tabl,nonn
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AUTHOR
| Omar E. Pol (info(AT)polprimos.com), Jul 09 2009
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EXTENSIONS
| More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 20 2009
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