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A247953 Numbers n such that 2^n + 33 is prime. 4
2, 3, 6, 11, 12, 14, 15, 20, 30, 60, 68, 75, 108, 116, 135, 206, 210, 410, 446, 558, 851, 1482, 1499, 2039, 2051, 4196, 7046, 7155, 8735, 10619, 18420, 20039, 46719, 75348, 179790, 203018, 434246 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Some terms correspond to probable primes. Lifchitz link shows the terms 179790 found by Donovan Johnson and 203018 by Lelio R Paula. - Jens Kruse Andersen, Sep 30 2014

a(38) > 5*10^5. - Robert Price, Nov 07 2015

LINKS

Table of n, a(n) for n=1..37.

Henri & Renaud Lifchitz, PRP Records, search for 2^n+33

MAPLE

A247957:=n->`if`(isprime(2^n+33), n, NULL): seq(A247957(n), n=0..1000); # Wesley Ivan Hurt, Sep 28 2014

MATHEMATICA

Select[Range[10000], PrimeQ[2^# + 33] &]

PROG

(MAGMA) /* The code gives only the terms up to 851: */ [n: n in [1..1400]| IsPrime( 2^n + 33 )];

(PARI) is(n)=ispseudoprime(2^n+33) \\ Charles R Greathouse IV, Feb 20 2017

CROSSREFS

Cf. similar sequences listed in A247952.

Sequence in context: A296444 A038752 A125714 * A284091 A004038 A152038

Adjacent sequences:  A247950 A247951 A247952 * A247954 A247955 A247956

KEYWORD

nonn,more

AUTHOR

Vincenzo Librandi, Sep 28 2014

EXTENSIONS

a(30)-a(34) from Jens Kruse Andersen, Sep 30 2014

a(35)-a(36) (discovered by Donovan Johnson and Lelio R Paula, respectively; see the Lifchitz link) added by Robert Price, Oct 04 2015

a(37) from Robert Price, Nov 07 2015

STATUS

approved

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Last modified June 25 10:29 EDT 2019. Contains 324351 sequences. (Running on oeis4.)