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A289353
Primes p such that (p,p+4) is a pair of cousin primes and p == 7 (mod 10).
2
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
1,1
COMMENTS
For cousin primes (p,p+4) such that p == 9 (mod 10), see A074822.
Members of A023200 with a last digit of 7. - Iain Fox, Dec 22 2017
LINKS
EXAMPLE
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).
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
MATHEMATICA
Select[10 Range[0, 660] + 7, PrimeQ[#] && PrimeQ[# + 4] &] (* Robert G. Wilson v, Dec 11 2017 *)
PROG
(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]);
(PARI) isok(p) = isprime(p) && isprime(p+4) && ((p % 10) == 7); \\ Michel Marcus, Jul 03 2017
(PARI) is(n)=n%30==7 && isprime(n+4) && isprime(n) \\ Charles R Greathouse IV, Jul 13 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Muniru A Asiru, Jul 03 2017
STATUS
approved