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A216300
Numbers k such that 10k+3 is composite but 10k+1, 10k+7, 10k+9 are all prime.
1
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
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 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
V. Raman, Sep 03 2012
STATUS
approved