A159064 Emirps which remain primes when rotated by 180 degrees on a digital clock display.
199, 1061, 1091, 1109, 1181, 1601, 1669, 1811, 1901, 10061, 10069, 10091, 10909, 11909, 16001, 18691, 18911, 19001, 19661, 19801, 101119, 101611, 106681, 106699, 106861, 108881, 109609, 109891, 110119, 110881, 110989, 111119, 111869, 111919, 116911
Offset: 1
Examples
1109 is an emirp (prime, and the reverse 9011 is also prime), it contains only digits 0,1,6,8 or 9 and can be rotated to form 6011, which is also prime. So 1109 is in the sequence.
Crossrefs
Cf. A145750.
Extensions
18691 and 18911 inserted, extended by R. J. Mathar, Apr 05 2009
Comments