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A060044
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Triangle of generalized sum of divisors function, read by rows.
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7
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1, -1, 1, 4, -1, -5, 1, 6, 1, 3, -4, -1, -2, 8, 1, 1, -13, -2, -5, 13, 1, 10, 23, -6, -1, -11, -25, 12, 1, 12, 27, -20, -2, -21, -49, 14, 3, 31, 74, -8, 1, 5, -13, -62, 24, -1, -4, 23, 85, -29, 1, 2, -42, -132, 18, -2, -8, 42, 165, -13, 3, 14, -42, -195, 20, -4, -20, 43, 229, -30
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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COMMENTS
| Lengths of rows are 1 1 2 2 2 3 3 3 3 ... (A003056).
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REFERENCES
| P. A. MacMahon, Divisors of numbers and their continuations in the theory of partitions, Proc. London Math. Soc., (2) 19 (1919), 75-113; Coll. Papers II, pp. 303-341.
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FORMULA
| T(n, k) = sum of (-1)^(k+s_1+s_2+...+s_k) * s_1*s_2*...*s_k where s_1, s_2, ..., s_k are such that s_1*m_1 + s_2*m_2 + ... + s_k*m_k = n and the sum is over all such k-partitions of n.
G.f. for k-th diagonal (the k-th row of the sideways triangle shown in the example): Sum_{ m_1 < m_2 < ... < m_k} q^(m_1+m_2+...+m_k)/((1+q^m_1)*(1+q^m_2)*...*(1+q^m_k))^2 = Sum_n T(n, k)*q^n.
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EXAMPLE
| Triangle turned on its side begins:
1 -1 4 -5 6 -4 .8 -13 13 etc
.... 1 -1 1 .3 -2 ..1 -5 etc
............ 1 -1 ..1 -2 etc
For example, T(8,3) = 1.
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CROSSREFS
| Diagonals give A002129, A002130, A060045. Cf. A060043, A060177.
Sequence in context: A132588 A195986 A046785 * A019303 A107463 A157104
Adjacent sequences: A060041 A060042 A060043 * A060045 A060046 A060047
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KEYWORD
| sign,tabf,easy,nice
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Mar 19 2001
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EXTENSIONS
| More terms from Naohiro Nomoto (n_nomoto(AT)yabumi.com), Jan 24 2002
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