login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A082092 Composite k such that d(k) < d(sigma(k)), i.e., A000005(k) < A000005(A000203(k)). 1
6, 10, 14, 15, 20, 21, 22, 24, 26, 27, 28, 30, 33, 34, 35, 38, 39, 40, 42, 44, 45, 46, 49, 51, 54, 55, 56, 57, 58, 60, 62, 63, 65, 66, 68, 69, 70, 74, 76, 77, 78, 82, 85, 86, 87, 88, 91, 92, 93, 94, 95, 96, 99, 102, 104, 105, 106, 108, 110, 111, 114, 115, 116, 117, 118, 119 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Not identical with A069116.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

EXAMPLE

For n=27: d(27)=4, sigma(27) = 1 + 3 + 9 + 27 = 40, d(40) = 8 > d(27);

27 is not in A069116.

MATHEMATICA

df[x_] := Sign[ -DivisorSigma[0, x]+DivisorSigma[0, DivisorSigma[1, x]]] Do[s=df[n]; If[Equal[s, 1]&&!PrimeQ[n], Print[n]], {n, 1, 1000}]

CROSSREFS

Cf. A000005, A000203, A037197, A069116, A073803, A073804.

Sequence in context: A080364 A325230 A227299 * A069116 A063763 A115956

Adjacent sequences:  A082089 A082090 A082091 * A082093 A082094 A082095

KEYWORD

nonn

AUTHOR

Labos Elemer, Apr 10 2003

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 14 05:36 EST 2019. Contains 329978 sequences. (Running on oeis4.)