A064975 Numbers k such that 10*k-1, 10*k-3, 10*k-7 and 10*k-9 are all prime.
2, 11, 20, 83, 149, 188, 209, 326, 347, 566, 944, 1301, 1565, 1574, 1607, 1805, 1892, 1943, 2102, 2228, 2531, 3173, 3485, 4379, 5135, 5534, 6299, 6722, 6950, 7223, 7727, 7970, 8105, 8273, 8882, 9785, 9914, 10112, 10985, 11654, 11930, 12221, 13547
Offset: 1
Crossrefs
Cf. A115095 (essentially the same).
Programs
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Mathematica
Select[Range[10^5], PrimeQ[10# - 1] && PrimeQ[10# - 3] && PrimeQ[10# - 7] && PrimeQ[10# - 9] &]