login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A068400 Numbers n such that sigma(n)=phi(n*bigomega(n)). 0
248, 357, 1045, 3596, 3956, 4064, 5396, 8636, 20026, 20320, 23374, 24871, 25714, 29029, 33915, 35074, 39585, 41656, 50065, 55154, 56134, 56536, 58435, 61344, 64285, 74613, 79000, 87087, 87685, 137885, 140335, 142240 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Comment from Giovanni Resta, Nov 15 2006: For all the numbers listed, gcd(n!-1,2^n+1) = 2n+1. Is this always true? Reply from Max Alekseyev, Nov 16 2006: This is plausible and true for n up to 45000.

LINKS

Table of n, a(n) for n=1..32.

CROSSREFS

Sequence in context: A187398 A065146 A064977 * A240967 A230856 A109478

Adjacent sequences:  A068397 A068398 A068399 * A068401 A068402 A068403

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, Mar 02 2002

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 24 17:57 EDT 2022. Contains 354043 sequences. (Running on oeis4.)