A289353 Primes p such that (p,p+4) is a pair of cousin primes and p == 7 (mod 10).
7, 37, 67, 97, 127, 277, 307, 397, 457, 487, 757, 877, 907, 937, 967, 1087, 1297, 1447, 1567, 1597, 1867, 2137, 2347, 2377, 2437, 2617, 2707, 2797, 2857, 3037, 3187, 3217, 3457, 3697, 3847, 3877, 3907, 4447, 5077, 5167, 5227, 5347, 5437, 5527, 5647, 5737, 5857, 6007, 6217, 6547, 6577
Offset: 1
Keywords
Examples
The pair of cousin prime (3,7) is not a member since 3 mod 10 = 3. For p = 97, we get that (97,101) is a cousin prime pair and 97 == 7 (mod 10).
Links
- Muniru A Asiru, Table of n, a(n) for n = 1..10000
Programs
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GAP
P:=Filtered([1..10000],IsPrime);; P1:=List(Filtered(Filtered(List([1..Length(P)-1],n->[P[n],P[n+1]]),i->i[2]-i[1]=4),j->j[1] mod 5 =2),k->k[1]);
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Maple
a:={}: for i from 1 to 1500 do if isprime(ithprime(i)+4) and ithprime(i) mod 10 = 7 then a:={op(a),ithprime(i)}: fi: od: a; # Muniru A Asiru, Aug 04 2017
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Mathematica
Select[10 Range[0, 660] + 7, PrimeQ[#] && PrimeQ[# + 4] &] (* Robert G. Wilson v, Dec 11 2017 *)
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PARI
isok(p) = isprime(p) && isprime(p+4) && ((p % 10) == 7); \\ Michel Marcus, Jul 03 2017
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PARI
is(n)=n%30==7 && isprime(n+4) && isprime(n) \\ Charles R Greathouse IV, Jul 13 2017
Comments