A247269 Primes p such that p + m^2 is prime for all m in {2,4,6,8,10,12,14,16,18}.
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
Keywords
Links
- Zak Seidov, Table of n, a(n) for n = 1..1592
Programs
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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
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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
Comments