A153166 - OEIS

A153166

Numbers k with property that 6*k+1 is prime and uses only digits 2 and 3.

37, 5372, 5387, 5537, 38722, 38887, 53872, 388722, 388887, 537037, 537222, 538887, 555372, 3703887, 3705372, 3705387, 3870372, 3870537, 3887037, 5387037, 5537037, 37220537, 37222222, 38705372, 38705537, 38870372, 38870537, 53703887

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OFFSET

1,1

COMMENTS

a(n) = (A153165(n)-1)/6.

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

pd23Q[n_]:=Module[{c=6n+1}, PrimeQ[c]&&Union[IntegerDigits[c]]=={2, 3}]; Select[ Range[ 54000000], pd23Q] (* Harvey P. Dale, Feb 08 2013 *)

Table[Select[(#-1)/6&/@Select[FromDigits/@Tuples[{2, 3}, n], OddQ[#] && PrimeQ[ #]&], IntegerQ], {n, 9}]//Flatten (* Harvey P. Dale, Oct 04 2016 *)

CROSSREFS

Cf. A153165.

Sequence in context: A219409 A232302 A363871 * A153168 A195215 A183481

Adjacent sequences: A153163 A153164 A153165 * A153167 A153168 A153169

KEYWORD

nonn,base

AUTHOR

Zak Seidov, Dec 20 2008

STATUS

approved