A145474 -id:A145474 - cp's OEIS frontend

A145479 Primes p such that (31+p)/2 is prime.

3, 7, 31, 43, 103, 127, 163, 223, 271, 283, 331, 367, 523, 631, 643, 727, 787, 811, 883, 967, 1051, 1063, 1123, 1171, 1231, 1291, 1423, 1447, 1471, 1483, 1543, 1627, 1723, 1783, 1951, 1987, 2011, 2143, 2203, 2311, 2371, 2467, 2551, 2731, 2767, 2887, 3067

Offset: 1

Artur Jasinski, Oct 11 2008

nonn

All terms are congruent to 3 mod 4 and (with the exception of the first term) to 7 mod 12.

Ivan Neretin, Table of n, a(n) for n = 1..10000

Cf. A092109, A145471, A145472, A145473, A145474, A145475, A145476, A145477, A145478, A145479, A155480.

aa = {}; k = 31; Do[If[PrimeQ[(k + Prime[n])/2], AppendTo[aa, Prime[n]]], {n, 1, 500}];aa
Select[Prime[Range[500]],PrimeQ[(31+#)/2]&] (* Harvey P. Dale, Feb 05 2012 *)

list(n)=my(t=1, p, i=1); while(i2&&isprime((31+p)/2),print1(p, ", "))) \\ Anders Hellström, Jan 23 2017

A145488 Numbers k such that 6k+13 is prime and 12k+13 is also prime.

Original entry on oeis.org

0, 4, 5, 8, 14, 15, 19, 25, 28, 30, 33, 35, 44, 49, 50, 54, 60, 68, 70, 85, 88, 93, 99, 100, 103, 120, 123, 133, 140, 144, 145, 149, 154, 168, 170, 173, 175, 179, 184, 190, 198, 215, 228, 235, 245, 253, 259, 264, 268, 274, 275, 280, 285, 288, 294

Offset: 1

Artur Jasinski, Oct 11 2008

nonn

Ivan Neretin, Table of n, a(n) for n = 1..10000

Cf. A063908-A063913, A092109, A145471-A145490.

select(k -> isprime(6*k+13) and isprime(12*k+13), [$0..1000]); # Robert Israel, Jan 23 2017

aa = {}; k = 13; Do[If[PrimeQ[(k + Prime[n])/2], AppendTo[aa, (Prime[n] - k)/12]], {n, 1, 500}]; aa

a(n) = (A145474(n)-13)/12.

Definition corrected by Ivan Neretin, Jan 23 2017

cp's OEIS Frontend

A145479 Primes p such that (31+p)/2 is prime.

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