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!)
A157968 2^n - 1 (A000225) where n is nonprime number (A141468). 0
0, 1, 15, 63, 127, 255, 511, 1023, 4095, 16383, 32767, 65535, 262143, 1048575, 2097151, 4194303, 16777215, 33554431, 67108863, 134217727, 268435455, 1073741823, 4294967295 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
COMMENTS
a(0) = 0 since 2^0 - 1 = 0 and 0 is nonprime, a(1) = 1 since 2^1 - 1 = 1 and 1 is nonprime, a(2) = 15 since 2^4 - 1 = 15 and 4 is nonprime, ...
LINKS
CROSSREFS
Sequence in context: A066584 A065915 A062965 * A141759 A335574 A305616
KEYWORD
nonn
AUTHOR
Jani Melik, Mar 10 2009
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 March 19 04:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)