The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A107639 Smallest prime a such that (a*b)^2 + a*b -1 is prime with b prime = 2^(2*n) - 2^n - 1, see A098845 for n. 0
5, 7, 31, 11, 5, 3, 809, 661, 139, 73, 521, 701, 131, 487, 89, 211, 733, 3011, 311, 8837, 2837, 8831, 1733, 401, 983, 17881, 1783, 19553, 13859 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
2^4-2^2-1=3=b(1) prime, (3*3)^2+3*3-1=89 prime so a(1)=3
2^8-2^4-1=239=b(2) prime, (7*239)^2+7*239-1=2800601 prime so a(2)=7
CROSSREFS
Cf. A098845.
Sequence in context: A081630 A307532 A135324 * A069688 A158323 A025119
KEYWORD
hard,more,nonn
AUTHOR
Pierre CAMI, Jun 10 2005
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 21 08:56 EDT 2024. Contains 372733 sequences. (Running on oeis4.)