A138537 Primes p_n for which A140141(n) = 2p_n, where p_n = n-th prime (A000040).

11, 23, 29, 31, 47, 53, 59, 67, 71, 79, 83, 103, 107, 127, 131, 137, 139, 149, 151, 167, 173, 179, 191, 197, 199, 211, 223, 227, 229, 239, 251, 263, 269, 271, 283, 293, 307, 311, 317, 331, 347, 359, 367, 373, 379, 383, 389, 419, 431, 439, 443, 463, 467, 479

Offset: 1

Author

Vladimir Shevelev, May 10 2008

Keywords

• nonn

Comments

Perhaps the same as A058340, but need proof. - Ray Chandler, May 20 2008

The first member of this sequence not in A058340 is 295937. - Robert Israel, Aug 12 2016

Links

• Robert Israel, Table of n, a(n) for n = 1..20000

Crossrefs

Cf. A000010, A000040, A039649, A058340, A140141.

Programs

Maple

filter:= n -> isprime(n) and numtheory:-invphi(numtheory:-phi(n))[2] = 2*n:
select(filter, [seq(i,i=2..1000)]); # Robert Israel, Aug 12 2016

Extensions

Corrected and extended by Ray Chandler, May 20 2008