A356498 Primes p such that 100*p + 11 is also prime.

2, 3, 23, 41, 83, 101, 107, 113, 137, 179, 233, 239, 251, 281, 293, 353, 359, 401, 419, 479, 503, 557, 563, 569, 587, 683, 701, 743, 809, 839, 857, 863, 941, 953, 977, 1049, 1091, 1103, 1193, 1217, 1277, 1283, 1361, 1367, 1427, 1487, 1499, 1523, 1607, 1619, 1847, 1871, 1877, 1889, 1907, 1949, 1973

Offset: 1

Author

Daniel Blam, Aug 09 2022

Keywords

• nonn

Comments

100*p + 11 has the effect of appending 11 to p.

Primes of the form 3*k + 1 are never in this sequence, as 100*(3*k + 1) + 11 can be simplified to 3*(100*k + 37).

Examples

			2 is a term, as 100*2 + 11 is 211, which are both prime.
101 is a term, as 100*101 + 11 is 10111 which are both prime.
		

Crossrefs

Cf. A000040, A002476 (primes of the form 3*k+1).

Similar to A023237.

Programs

Python

from sympy import isprime
print([k for k in range(2000) if isprime(100*k+11) and isprime(k)])