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A068715 Primes of the form 10*3^k + 1. 2
11, 31, 271, 811, 21871, 196831, 5314411, 3874204891, 313810596091, 46383976865881019793281501678905914543189676980091, 2738927449953408337773479392637715347860807235997334411 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..19

EXAMPLE

21871 is a member as it is a concatenation of 2187 (= 3^7) and 1.

MATHEMATICA

Select[Table[10*3^n+1, {n, 0, 300}], PrimeQ](* Vincenzo Librandi, Dec 08 2011 *)

PROG

(MAGMA) [a: n in [0..200] | IsPrime(a) where a is 10*3^n + 1]; // Vincenzo Librandi, Dec 08 2011

CROSSREFS

Cf. A068712, A068714.

Sequence in context: A093382 A098264 A023279 * A093881 A328715 A163763

Adjacent sequences:  A068712 A068713 A068714 * A068716 A068717 A068718

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Mar 05 2002

EXTENSIONS

More terms from Sascha Kurz, Mar 17 2002

STATUS

approved

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Last modified July 24 08:43 EDT 2021. Contains 346273 sequences. (Running on oeis4.)