OFFSET
1,2
COMMENTS
The first four terms correspond to negative primes. Dropping them gives A096820. - Joerg Arndt, Oct 05 2012
MATHEMATICA
Do[ If[ PrimeQ[ 2^n - 21 ], Print[ n ] ], {n, 1, 3000} ]
PROG
(PARI) is(n)=isprime(2^n - 21) \\ Charles R Greathouse IV, Aug 08 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Sep 16 2000
EXTENSIONS
a(25)-a(34) from A096820, by Bruno Berselli, Oct 05 2012
a(35)-a(36) from A096820, by Robert Price, Aug 08 2016
STATUS
approved