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A032621 Numbers n such that n concatenated with n + 6 is a prime. 1
1, 11, 13, 17, 25, 31, 35, 43, 65, 71, 83, 95, 97, 101, 125, 127, 137, 151, 155, 157, 161, 163, 167, 187, 197, 203, 205, 211, 217, 221, 223, 227, 233, 235, 245, 251, 257, 263, 265, 271, 283, 317, 331, 335, 337, 341, 353, 355, 373, 385, 391, 401, 427, 433 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..54.

MATHEMATICA

Select[Range[1, 501, 2], PrimeQ[FromDigits[Join[IntegerDigits[#], IntegerDigits[ #+6]]]]&] (* Harvey P. Dale, Nov 17 2013 *)

CROSSREFS

Cf. A032611.

Sequence in context: A048059 A106076 A006489 * A289701 A250402 A052031

Adjacent sequences:  A032618 A032619 A032620 * A032622 A032623 A032624

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, May 15 1998

STATUS

approved

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Last modified June 17 15:26 EDT 2019. Contains 324194 sequences. (Running on oeis4.)