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A068712 Primes of the form 5*2^k + 3. 5
13, 23, 43, 83, 163, 643, 1283, 10243, 20483, 1310723, 5242883, 335544323, 1342177283, 21474836483, 85899345923, 43980465111043, 87960930222083, 5629499534213123, 22517998136852483, 1441151880758558723 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..38

EXAMPLE

1283 is a term as a concatenation of 2^7 and 3.

MATHEMATICA

Select[5*2^Range[60]+3, PrimeQ]  (* Harvey P. Dale, Feb 04 2011 *)

PROG

(PARI) for(n=1, 150, if(isprime(2^n*5+3)==1, print1(2^n*5+3, ", ")))

(MAGMA) [a: n in [1..100] | IsPrime(a) where a is 5*2^n + 3]; // Vincenzo Librandi, Dec 08 2011

CROSSREFS

Cf. A058586, A068715, A144487, A211486.

Sequence in context: A256177 A320752 A213665 * A103166 A154863 A194156

Adjacent sequences:  A068709 A068710 A068711 * A068713 A068714 A068715

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Mar 05 2002

EXTENSIONS

More terms from Benoit Cloitre, Mar 09 2002

STATUS

approved

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Last modified July 25 23:39 EDT 2021. Contains 346294 sequences. (Running on oeis4.)