A236529 Primes arising in A069607.

5, 53, 5323, 53231, 532313, 5323139, 532313921, 5323139219, 532313921921, 53231392192123, 5323139219212343, 53231392192123433, 5323139219212343323, 53231392192123433237, 5323139219212343323721, 532313921921234332372189, 53231392192123433237218937, 5323139219212343323721893721

Offset: 1

Author

Derek Orr, Jan 27 2014

Keywords

• nonn
• base

Comments

a(n+1) is the next smallest prime beginning with a(n). Initial term is 5.

Examples

			a(1) = 5.
a(2) is the next smallest prime that begins with 5, so a(2) = 53.
a(3) is the next smallest prime that begins with 53, so a(3) = 5323.
...and so on.
		

Crossrefs

Cf. A069607, A110773, A048553.

Programs

Python

import sympy
from sympy import isprime
def b(x):
  num = str(x)
  n = 1
  while n < 10**3:
    new_num = str(x) + str(n)
    if isprime(int(new_num)):
      print(int(new_num))
      x = new_num
      n = 1
    else:
      n += 1
b(5)