A067267 - OEIS

A067267

Numbers n such that n, 10*n+1, 10*n+3, 10*n+7 and 10*n+9 are all primes.

19, 6949, 10111, 15727, 20149, 24799, 26041, 26881, 29587, 29947, 40213, 41203, 44257, 46747, 47701, 49057, 50023, 51061, 55921, 66109, 66643, 73939, 76819, 79579, 95947, 106501, 110083, 111781, 112213, 114679

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OFFSET

1,1

COMMENTS

All terms == 1 (mod 6). - Robert Israel, Jan 22 2018

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

EXAMPLE

a(1)=19 because 191, 193, 197 and 199 are all prime.

MAPLE

select(t -> andmap(isprime, [t, 10*t+1, 10*t+3, 10*t+7, 10*t+9]), [seq(i, i=1..2*10^5, 6)]); # Robert Israel, Jan 22 2018

MATHEMATICA

okQ[n_]:=Module[{n10=10n}, And@@PrimeQ[{n10+1, n10+3, n10+7, n10+9}]]

Select[Prime[Range[20000]], okQ] (* Harvey P. Dale, Dec 13 2010 *)

Select[Prime[Range[11000]], AllTrue[10#+{1, 3, 7, 9}, PrimeQ]&] (* Harvey P. Dale, Feb 23 2022 *)

CROSSREFS

Cf. A007811.

Sequence in context: A172662 A201303 A013724 * A340165 A124989 A265964

Adjacent sequences: A067264 A067265 A067266 * A067268 A067269 A067270

KEYWORD

nonn

AUTHOR

Sudipta Das (juitech(AT)vsnl.net), Feb 21 2002

STATUS

approved