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A127739
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Triangle read by rows, in which row n contains the triangular number T(n) = A000217(n) repeated n times.
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3
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1, 3, 3, 6, 6, 6, 10, 10, 10, 10, 15, 15, 15, 15, 15, 21, 21, 21, 21, 21, 21, 28, 28, 28, 28, 28, 28, 28
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Row sums = A002411: (1, 6, 18, 40, 75,...).
Central terms: T(2*n-1,n) = A000384(n). [Reinhard Zumkeller, Mar 18 2011]
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LINKS
| Reinhard Zumkeller, Rows n=1..100 of triangle, flattened
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EXAMPLE
| First few rows of the triangle are:
1;
3, 3;
6, 6, 6;
10, 10, 10, 10;
15, 15, 15, 15, 15;
...
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MATHEMATICA
| Table[n(n+1)/2, {n, 100}, {n}]//Flatten (* Zak Seidov Mar 19 2011 *)
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PROG
| (Haskell)
a127739 n k = a127739_tabl !! (n-1) !! (k-1)
a127739_row n = a127739_tabl !! (n-1)
a127739_tabl = zipWith ($) (map replicate [1..]) $ tail a000217_list
-- Reinhard Zumkeller, Feb 03 2012, Mar 18 2011
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CROSSREFS
| Cf. A000217, A002411.
Cf. A057944.
Sequence in context: A072464 A160745 A105676 * A175394 A070318 A023842
Adjacent sequences: A127736 A127737 A127738 * A127740 A127741 A127742
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KEYWORD
| nonn,tabl
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AUTHOR
| Gary W. Adamson (qntmpkt(AT)yahoo.com), Jan 27 2007
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