A136079 Father primes of order 10.

83, 167, 251, 293, 419, 503, 797, 881, 1259, 1301, 1427, 1511, 1553, 1889, 2141, 2267, 2309, 2393, 2687, 2897, 2939, 3191, 3527, 3779, 3821, 4073, 4157, 4451, 4703, 4787, 5039, 5081, 5417, 5669, 5711, 6173, 6551, 6971, 7307, 7349, 7433, 7559, 7727, 7853

Offset: 1

Author

Artur Jasinski, Dec 12 2007

Keywords

• nonn

Comments

For smallest father primes of order n, see A136026 (also definition). For father primes of orders 1,2,...,9, see A094524, A136071, A136072, A136073, A136074, A136075, A136076, A136077, A136078, respectively.

From Bob Selcoe, Apr 25 2014: (Start)

In general, a father prime, p', of order k is of the form p'=2k+(2k+1)*p for some prime, p. In this sequence, k=10, and so each prime is of the form p'=20+21p where p ranges over {3,7,11,13,19,23,...}. Thus a father prime p' has order k when (p'-2k)/(2k+1) is prime.

Father primes (p') of order k will be of the form: p'(mod (4k+2))=4k+1, or p'=(4k+2)*j-1, j>=2. For this sequence: k=10, 4k+2=42; j={2,4,6,7,10,12,...}. So for example, j=7 generates a father prime because 42*7-1 = 293 AND (293-(2*10))/(2*10+1) = 13, since both 13 and 293 are prime. Note that not all j such that (4k+2)*j-1 is prime will produce a father prime. In this example, when j=11, 42*11-1=461 (prime); but (461-(2*10))/(2*10+1) = 21 (not prime). (End)

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A023208, A094524, A136019, A136020, A136026, A136027, A136071, A136072, A136073, A136074, A136075, A136076, A136077, A136078, A136080.

Programs

Mathematica

n = 10; a = {}; Do[If[PrimeQ[(Prime[k] - 2n)/(2n + 1)], AppendTo[a, Prime[k]]], {k, 1, 1500}]; a