OFFSET
1,1
COMMENTS
Primes of the form 10n+7 such that 10n+1, 10n+3, and 10n+9 are composite. - Charles R Greathouse IV, Sep 06 2012
LINKS
V. Raman, Table of n, a(n) for n = 1..10000
FORMULA
a(n) ~ 4n log n. - Charles R Greathouse IV, Sep 06 2012
MATHEMATICA
t = {}; Do[ps = Select[Range[10*n, 10*n + 9], PrimeQ]; If[ps == {10*n + 7}, AppendTo[t, ps[[1]]]], {n, 0, 529}]; t (* T. D. Noe, Sep 04 2012 *)
PROG
(Magma) [p: p in PrimesUpTo(4000) | p mod 10 eq 7 and IsOne(#PrimesInInterval(10*t+1, 10*t+9)) where t is Floor(p/10)]; // Bruno Berselli, Sep 14 2012
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
V. Raman, Sep 03 2012
STATUS
approved