[seqfan] Emirps (sorted by period) with with unique period length
Jonathan Post
jvospost3 at gmail.com
Wed Oct 6 22:03:28 CEST 2010
37, 333667, 909091
no more through A007615(15).
A007615 INTERSECTION A006567.
Primes p whose reversal is a different prime, and which are the only
primes p = A007615 (n) such that decimal expansion of 1/p has unique
(nontrivial) period A007498 (A007615(n)).
Examples:
a(1) = 37 because R(37) = 73 is prime, and 37 is the unique prime p
such that 1/p has period 1/37 = 3.
a(2) = 333667 because R(333667) = 766333 is prime, and 333667 is the
unique prime p such that 1/p has period 1/333667 = 9.
a(3) = 909091 because R(909091) = 190909 is prime, and 909091 is the
unique prime p such that 1/p has period 1/909091 = 14.
Base. More.
Cf. 000040, A004086, A006567, A007498, A007615.
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