A371865 Primes whose second to ninth digits are 23456789.

623456789, 1234567891, 2234567891, 2234567893, 2234567897, 3234567893, 7234567891, 12345678923, 12345678929, 12345678949, 22345678907, 22345678913, 22345678933, 22345678963, 22345678967, 22345678981, 32345678929, 32345678933, 32345678951, 32345678957, 42345678901, 42345678911, 42345678937, 42345678941

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

R:= 623456789: count:= 1:
for d from 0 while count < 100 do
  for a from 1 to 9 while count < 100 do
    for b from 1 to 10^d-1 by 2 while count < 100 do
      x:= b + 10^d*(23456789 + 10^8*a);
      if isprime(x) then
         count:= count+1; R:= R, x;
      fi
od od od:
R;

Prog

(Python)
from itertools import count, islice
from sympy import primerange
def A371865_gen(): # generator of terms
    for l in count(0):
        m = 10**l
        for a in range(1, 10):
            b = (a*10**8+23456789)*m
            yield from primerange(b, b+m)
A371865_list = list(islice(A371865_gen(), 20)) # Chai Wah Wu, Apr 09 2024

Crossrefs

Cf. A371833, A371845.

Sequence in context: A184216 A123705 A237364 * A251498 A233848 A343077

Adjacent sequences: A371862 A371863 A371864 * A371866 A371867 A371868

Keyword

nonn,base,look

Author

Zak Seidov and Robert Israel, Apr 09 2024

Extensions

a(1) = 623456789 inserted by Christian Sievers, Apr 10 2024

Status

approved