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A247269
Primes p such that p + m^2 is prime for all m in {2,4,6,8,10,12,14,16,18}.
4
163, 409333, 1483087, 1867783, 222640867, 258001837, 371305267, 748576753, 828497443, 1235054137, 2059599067, 5767711867, 5929920613, 8965599883, 9055004953, 9170160343, 9655686727, 9670115977, 9671300983, 10646399437, 12253792783, 12627473917, 19635778453
OFFSET
1,1
COMMENTS
All terms are == 1 mod 6, and == {7, 13} mod 30.
Subsequence of A246842.
PROG
(PARI)
forprime(p=1, 10^12, c=0; for(i=1, 9, if(ispseudoprime(p+(2*i)^2), c++); if(!ispseudoprime(p+(2*i)^2), break)); if(c==9, print1(p, ", "))) \\ Derek Orr, Sep 11 2014
(PARI) is(n)=my(t=n%5); if(t!=2 && t!=3, return(0)); forstep(i=4, 18, 2, if(!isprime(n+i^2), return(0))); isprime(n) && isprime(n+4)
p=2; forprime(q=3, 1e12, if(q-p==4 && is(p), print1(p", ")); p=q) \\ Charles R Greathouse IV, Sep 11 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Sep 11 2014
STATUS
approved