A379426 Prime terms in A287353.

2, 23, 2357, 23581, 2358247, 235824913, 235824916247, 2358249162515829584909, 235824916251582958491829824917162558516292249258249589629182571583855789, 2358249162515829584918298249171625585162922492582495896291825715838558298516316558918298250261

Offset: 1

Author

Ya-Ping Lu, Dec 22 2024

Keywords

• nonn

Comments

Primes Sum_{i=1..k} 10^(k-i)*prime(i) for some k.

Examples

			k    prime(k)  A287353(k)  n    a(n)
---  --------  ----------  ---  -------
1    2         2           1    2
2    3         23          2    23
3    5         235
4    7         2357        3    2357
5    11        23581       4    23581
6    13        235823
7    17        2358247     5    2358247
		

Crossrefs

Cf. A013918, A069151, A287353.

Programs

Python

from sympy import isprime, nextprime
m = p = 0
while p < 500:
    p = nextprime(p); m = 10*m + p
    if isprime(m): print(m, end = ', ')