|
Search: id:A001600
|
|
|
| A001600 |
|
Harmonic means of divisors of harmonic numbers.
(Formerly M0609 N0220)
|
|
+0
9
|
|
| 1, 2, 3, 5, 6, 5, 8, 9, 11, 10, 7, 15, 15, 14, 17, 24, 24, 21, 13, 19, 27, 25, 29, 26, 44, 44, 29, 46, 39, 46, 27, 42, 47, 47, 54, 35, 41, 60, 51, 37, 48, 45, 49, 50, 49, 53, 77, 86, 86, 51, 96, 75, 70, 80, 99, 110, 81, 84, 13, 102, 82, 96, 114, 53, 108, 115, 105, 116, 91, 85, 105
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
Values of n*tau(n)/sigma(n) corresponding to terms of A001599, where tau(n) (A000005) is the number of divisors of n and sigma(n) is the sum of the divisors of n (A000203).
|
|
REFERENCES
|
Garcia, Mariano; On numbers with integral harmonic mean. Amer. Math. Monthly 61, (1954). 89-96.
O. Ore, On the averages of the divisors of a number, Amer. Math. Monthly, 55 (1948), 615-619.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
|
|
LINKS
|
T. D. Noe, Table of n, a(n) for n=1..115
Matthew M. Conroy, Home page (listed instead of email address)
Takeshi Goto, All harmonic numbers less than 10^14
Takeshi Goto, Table of a(n) for n=1..937
|
|
CROSSREFS
|
Cf. A001599, A090240 (sorted values).
Sequence in context: A054077 A082654 A072636 this_sequence A000036 A165081 A165089
Adjacent sequences: A001597 A001598 A001599 this_sequence A001601 A001602 A001603
|
|
KEYWORD
|
nonn,nice,easy
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com).
|
|
EXTENSIONS
|
More terms from Matthew Conroy (list1(AT)madandmoonly.com), Jan 15 2006
|
|
|
Search completed in 0.002 seconds
|
