|
Search: id:A002128
|
|
|
| A002128 |
|
Generalized sum of divisors function.
(Formerly M2784 N1119)
|
|
+0
2
|
|
| 1, 3, 9, 22, 42, 81, 140, 231, 351, 551, 783, 1134, 1546, 2142, 2835, 3758, 4818, 6237, 7826, 9885, 12159, 14974, 18261, 22113, 26511, 31668, 37611, 44149, 52074, 60660, 70569, 81396, 94311, 107317, 123879, 140049, 160154, 179949, 204867, 228137
(list; graph; listen)
|
|
|
OFFSET
|
6,2
|
|
|
REFERENCES
|
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
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.
|
|
FORMULA
|
G.f.: (t(1)^3-3*t(1)*t(2)+2*t(3))/6 where t(i) = Sum(x^(n*i)/(1-x^n)^(2*i),n=1..inf), i=1..3. - Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 21 2007
|
|
CROSSREFS
|
A diagonal of A060043.
Sequence in context: A098980 A063586 A131477 this_sequence A064808 A001937 A086817
Adjacent sequences: A002125 A002126 A002127 this_sequence A002129 A002130 A002131
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com).
|
|
EXTENSIONS
|
More terms from Naohiro Nomoto (n_nomoto(AT)yabumi.com), Jan 24 2002
More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 21 2007
|
|
|
Search completed in 0.002 seconds
|
