A189556 Prime numbers n such that x' = n has two solutions, where x' is the arithmetic derivative (A003415) of x.

31, 61, 71, 101, 103, 131, 199, 211, 241, 269, 359, 401, 421, 433, 439, 571, 619, 641, 661, 719, 727, 739, 751, 761, 811, 1019, 1051, 1063, 1193, 1277, 1279, 1303, 1307, 1321, 1451, 1471, 1499, 1613, 1619, 1667, 1697, 1721, 1723, 1783, 1879, 1949

Offset: 1

Author

T. D. Noe, Apr 24 2011

Keywords

• nonn

Comments

The primes in A189555.

Crossrefs

Cf. A003415.