A086402 Nontrivial numbers which are prime and yield another prime when their digits are sorted in descending order.

13, 17, 37, 79, 113, 131, 149, 157, 163, 167, 179, 181, 191, 197, 199, 241, 251, 281, 313, 337, 347, 359, 373, 389, 419, 461, 463, 491, 563, 571, 593, 613, 617, 683, 719, 787, 797, 839, 919, 1163, 1181, 1193, 1217, 1223, 1229, 1237, 1249, 1259, 1279, 1297

Offset

1,1

Comments

Primes with digits already in descending order (like 311 and 3221) are trivial cases and are therefore excluded.

Links

Table of n, a(n) for n=1..50.

Example

a(1)=13 because a descending sort of 13's digits yields 31 which is also prime. a(100)=2411 because a descending sort of 2411's digits yields 4211 which is also prime.

Crossrefs

Cf. A003459.

Sequence in context: A109308 A263241 A246944 * A358571 A271050 A039290

Adjacent sequences: A086399 A086400 A086401 * A086403 A086404 A086405

Keyword

base,nonn

Author

Chuck Seggelin (barkeep(AT)plastereddragon.com), Jul 07 2003

Status

approved