A330968 Prime numbers p such that 2*p - last digit of p is prime.

2, 3, 5, 7, 13, 19, 23, 31, 37, 43, 53, 59, 67, 79, 83, 113, 139, 157, 179, 193, 199, 211, 223, 229, 233, 263, 271, 277, 283, 307, 331, 359, 367, 373, 389, 397, 409, 419, 433, 443, 457, 487, 509, 547, 563, 569, 601, 613, 619, 643, 653, 661, 691, 709, 719, 727

Offset

1,1

Comments

Prime numbers p such that 2*p - (p mod 10) is prime.

Links

Table of n, a(n) for n=1..56.

Example

Prime number 19 is a term since 2 * 19 - (19 mod 10) = 2 * 19 - 9 = 29, a prime.

Prog

(PARI) forprime(p = 2, 1000, if(isprime(2*p - p%10), print1(p", ")))
(Magma) [p:p in PrimesUpTo(750)| IsPrime(2*p-(p mod 10))]; // Marius A. Burtea, Feb 07 2020

Crossrefs

Cf. A000040, A007652.

Sequence in context: A233134 A082885 A118371 * A153591 A038917 A124661

Adjacent sequences: A330965 A330966 A330967 * A330969 A330970 A330971

Keyword

nonn,base

Author

Dimitris Valianatos, Feb 06 2020

Status

approved