OFFSET
1,1
COMMENTS
Subsequence of A089201. - R. J. Mathar, Dec 08 2015
Contains all primes == 12253 (mod 27000), and therefore the sequence is infinite. - Robert Israel, Apr 21 2016
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..16574
MAPLE
filter:= proc(p) local d;
if not isprime(p) then return false fi;
for d in [-5, -3, 3, 5] do
if max(map(t -> t[2], ifactors(p+d)[2])) < 3 then return false fi;
od;
true
end proc:
select(filter, [seq(t, t=7..10^6, 2)]); # Robert Israel, Apr 21 2016
# alternative
isA166000 := proc(n)
if isprime(n) then
isA046099(n-3) and isA046099(n+3) and isA046099(n-5) and isA046099(n+5) ;
else
false;
end if;
end proc: # R. J. Mathar, Aug 14 2024
MATHEMATICA
f[n_]:=Max[Last/@FactorInteger[n]]; q=3; lst={}; Do[p=Prime[n]; If[f[p-5]>=q&&f[p-3]>=q&&f[p+3]>=q&&f[p+5]>=q, AppendTo[lst, p]], {n, 4*8!}]; lst
PROG
(PARI) ncf(n)={vecmax(factor(n)[, 2])>2}; forprime(p=5, 1e7, if(ncf(p+5)&&ncf(p+3)&&ncf(p-3)&&ncf(p-5), print1(p", "))) /* Charles R Greathouse IV, Oct 05 2009 */
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, Oct 03 2009
STATUS
approved