A216306 - OEIS

A216306

Values of k such that 10*k+3 and 10*k+7 alone are prime between 10*k and 10*k+9.

16, 67, 121, 220, 229, 247, 283, 295, 334, 361, 379, 394, 481, 592, 604, 673, 724, 757, 760, 772, 793, 844, 880, 913, 988, 1024, 1066, 1108, 1144, 1159, 1186, 1192, 1234, 1243, 1303, 1318, 1396, 1417, 1453, 1465, 1471, 1501, 1507, 1537, 1549, 1660, 1762, 1858

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OFFSET

1,1

LINKS

V. Raman, Table of n, a(n) for n = 1..10000

FORMULA

a(n) >> n log^2 n. - Charles R Greathouse IV, Sep 07 2012

MATHEMATICA

t = {}; Do[ps = Select[Range[10*n, 10*n + 9], PrimeQ]; If[ps == {10*n + 3, 10*n + 7}, AppendTo[t, n]], {n, 0, 2476}]; t (* T. D. Noe, Sep 04 2012 *)

Select[Range[2000], Boole[PrimeQ[10#+{1, 3, 7, 9}]]=={0, 1, 1, 0}&] (* Harvey P. Dale, Jul 20 2021 *)

CROSSREFS

Cf. A032352, A007811, A078494.