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!)
A264011 Exponents n such that 2^(2*n+1) - 3*2^n - 1 (A195461) is prime 0
2, 3, 4, 5, 8, 16, 27, 28, 33, 36, 48, 66, 90, 112, 508, 1036, 1041, 1560, 2208, 2668, 4388, 6097, 6517, 11353, 17284, 22385, 24740, 29805, 77188, 135219, 199237 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Obtained using a Lucas-Lehmer-type test due to Williams.

Next term > 200000.

LINKS

Table of n, a(n) for n=1..31.

H. C. Williams, A class of primality tests for trinomials which includes the Lucas-Lehmer test, Pacific J. Math. Volume 98, Number 2 (1982), 477-494.

PROG

(PARI) for(n=1, 10^9, if(ispseudoprime(2^(2*n+1) - 3*2^n - 1), print1(n, ", "))); \\ Joerg Arndt, Apr 08 2016

CROSSREFS

Cf. A195461.

Sequence in context: A333264 A247461 A281303 * A337280 A081711 A055638

Adjacent sequences:  A264008 A264009 A264010 * A264012 A264013 A264014

KEYWORD

nonn,more

AUTHOR

Fabrice Lavier, Jan 03 2016

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 February 26 11:15 EST 2021. Contains 341631 sequences. (Running on oeis4.)