login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A067235 Numbers n such that phi(4n-1) = sigma(n). 1
660, 744, 4216, 6460, 10780, 11880, 14688, 27820, 32524, 37464, 40120, 59964, 87124, 110770, 120934, 125764, 184264, 190564, 194584, 210324, 264280, 269514, 295144, 297388, 298840, 314974, 379204, 384750, 396256, 396520, 406296, 444244, 473524, 597480 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Are there any odd terms in the sequence?

LINKS

Donovan Johnson, Table of n, a(n) for n = 1..1000

PROG

(PARI) for(n=1, 10^9, if(eulerphi(4*n-1)==sigma(n), print(n))) /* Donovan Johnson, Aug 18 2012 */

CROSSREFS

Sequence in context: A198207 A171393 A023294 * A113171 A252519 A014362

Adjacent sequences:  A067232 A067233 A067234 * A067236 A067237 A067238

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Feb 20 2002

EXTENSIONS

More terms from Harvey P. Dale, Feb 26 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 18 08:58 EDT 2021. Contains 348067 sequences. (Running on oeis4.)