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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A000173 Unitary-sociable numbers (smallest member of each cycle). 3
30, 1482, 2418, 24180, 35238, 263820, 395730, 473298, 698130, 763620, 2212026, 2233554, 172459210, 209524210, 341354790, 384121920, 525150234, 530946330, 582129630, 1799281330, 2069510520, 2514290520, 3344596854, 5251502340 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

If n=product p_i^a_i, d=product p_i^c_i is a unitary divisor of n if each c_i is 0 or a_i.

REFERENCES

R. K. Guy, Unsolved Problems in Number Theory, 3rd edition, Sect. B7

LINKS

Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 01 2006, Table of n, a(n) for n = 1..44

David Moews, Perfect, amicable and sociable numbers

J. O. M. Pedersen, Tables of Aliquot Cycles

Eric Weisstein's World of Mathematics, Sociable Numbers

CROSSREFS

Cf. A034444, A003416, A097323.

Sequence in context: A002456 A107768 A048536 * A055351 A103917 A196464

Adjacent sequences:  A000170 A000171 A000172 * A000174 A000175 A000176

KEYWORD

nonn,nice

AUTHOR

N. J. A. Sloane

EXTENSIONS

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Nov 01 2006

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified May 25 08:37 EDT 2017. Contains 287015 sequences.