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!)
A161749 Smallest prime of the form x^(2n+1) - y^(2n-1), x,y >= 1. 0
3, 5, 127, 3299, 1967249047, 8191, 30450469261, 131071, 524287, 476562280296181, 70358283824461 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

For even n > 4 = 2m, x^(2m) - y^(2m-2) = (x^m)^2 - y^((m-1))^2 is divisible by x^m - y^(m-1) which is not prime. This accounts for the omission of even powers in the definition.

LINKS

Table of n, a(n) for n=1..11.

CROSSREFS

Sequence in context: A340823 A245442 A215239 * A240589 A180541 A103993

Adjacent sequences:  A161746 A161747 A161748 * A161750 A161751 A161752

KEYWORD

nonn

AUTHOR

Cino Hilliard, Jun 17 2009

EXTENSIONS

Incorrect program removed; definition confined to odd powers; added terms a(8)..a(11). - R. J. Mathar, Feb 27 2012

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 September 27 07:01 EDT 2022. Contains 357052 sequences. (Running on oeis4.)