A216300 Numbers k such that 10k+3 is composite but 10k+1, 10k+7, 10k+9 are all prime.

13, 160, 376, 391, 421, 547, 586, 712, 745, 748, 754, 808, 883, 985, 1006, 1210, 1291, 1333, 1375, 1462, 1513, 1588, 1702, 1798, 2203, 2269, 2302, 2353, 2497, 2584, 2854, 2920, 3205, 3358, 3436, 3583, 3823, 3832, 3856, 3982, 4003, 4084, 4138, 4339, 4402

Offset

1,1

Links

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

Formula

a(n) >> n log^3 n. - Charles R Greathouse IV, Sep 07 2012

Mathematica

t = {}; Do[ps = Select[Range[10*n, 10*n + 9], PrimeQ]; If[ps == {10*n + 1, 10*n + 7, 10*n + 9}, AppendTo[t, n]], {n, 0, 4738}]; t (* T. D. Noe, Sep 03 2012 *)
Select[Range[5000], Boole[PrimeQ[10 #+{1, 3, 7, 9}]]=={1, 0, 1, 1}&] (* Harvey P. Dale, Jan 29 2025 *)

Crossrefs

Cf. A032352, A007811, A078494.

Sequence in context: A205170 A205163 A118673 * A250417 A212785 A133180

Adjacent sequences: A216297 A216298 A216299 * A216301 A216302 A216303

Keyword

nonn

Author

V. Raman, Sep 03 2012

Status

approved