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Search: id:A049777
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| A049777 |
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Triangular array read by rows: T(m,n) = n + n+1 + ... + m = (m+n)(m-n+1)/2. |
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+0
7
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| 1, 3, 2, 6, 5, 3, 10, 9, 7, 4, 15, 14, 12, 9, 5, 21, 20, 18, 15, 11, 6, 28, 27, 25, 22, 18, 13, 7, 36, 35, 33, 30, 26, 21, 15, 8, 45, 44, 42, 39, 35, 30, 24, 17, 9, 55, 54, 52, 49, 45, 40, 34, 27, 19, 10, 66, 65, 63, 60, 56, 51, 45, 38, 30, 21, 11, 78, 77, 75, 72, 68, 63, 57, 50
(list; table; graph; listen)
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OFFSET
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1,2
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FORMULA
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Partial sums of A002260 row terms, starting from the right; e.g. row 3 of A002260 = (1, 2, 3), giving (6, 5, 3). - Gary W. Adamson (qntmpkt(AT)yahoo.com), Oct 23 2007
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EXAMPLE
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Rows: {1}; {3,2}; {6,5,3}; ...
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PROGRAM
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(PARI) {T(n, k) = if( k<1 | n<k, 0, (n + k) * (n - k + 1) / 2 )} /* Michael Somos Oct 06 2007 */
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CROSSREFS
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Row sums = A000330.
Cf. A002260.
Sequence in context: A164073 A090571 A088452 this_sequence A058401 A105027 A120913
Adjacent sequences: A049774 A049775 A049776 this_sequence A049778 A049779 A049780
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KEYWORD
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nonn,tabl
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AUTHOR
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Clark Kimberling (ck6(AT)evansville.edu)
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