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A216297
Values of k such that 10k + 7 is the only prime between 10k and 10k + 9.
1
9, 12, 30, 36, 39, 45, 48, 55, 58, 72, 78, 79, 87, 90, 93, 96, 108, 111, 144, 156, 159, 163, 165, 177, 184, 198, 243, 246, 261, 264, 270, 276, 277, 288, 289, 291, 292, 303, 313, 321, 340, 345, 360, 372, 384, 387, 390, 396, 417, 429, 432, 435, 450, 498, 507
OFFSET
1,1
FORMULA
a(n) ~ 0.4 n log n. - Charles R Greathouse IV, Sep 07 2012
MATHEMATICA
t = {}; Do[ps = Select[Range[10*n, 10*n + 9], PrimeQ]; If[ps == {10*n + 7}, AppendTo[t, n]], {n, 0, 639}]; t (* T. D. Noe, Sep 03 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
V. Raman, Sep 03 2012
STATUS
approved