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

1,1

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).

Links

Table of n, a(n) for n=1..57.

Example

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.

Prog

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

Crossrefs

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

Similar to A023237.

Sequence in context: A215353 A215305 A215282 * A309586 A386142 A090708

Adjacent sequences: A356495 A356496 A356497 * A356499 A356500 A356501

Keyword

nonn

Author

Daniel Blam, Aug 09 2022

Status

approved