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A145750
Primes which become emirps when rotated by 180 degrees on a digital clock display.
1
661, 1061, 1091, 1181, 1601, 1811, 1901, 6011, 6991, 10061, 10091, 10861, 11681, 16001, 16981, 19001, 19961, 60601, 60611, 69001, 106861, 108161, 108881, 109891, 110881, 116881, 116911, 118081, 118861, 119101, 119611, 160861, 161611, 168601, 169691
OFFSET
1,1
COMMENTS
The sequence contains all bemirps A048895.
Subsequence of A057770. [R. J. Mathar, Apr 05 2009]
EXAMPLE
1109 is a prime. After 2D rotation it is 6011, which is prime. However, 6011 is not an emirp because 1106 is not prime. So 1109 is not in the sequence.
CROSSREFS
Sequence in context: A252401 A171394 A243886 * A243889 A105978 A208180
KEYWORD
nonn,base
AUTHOR
Lekraj Beedassy, Apr 04 2009
EXTENSIONS
1109 removed, 6011 inserted etc. by R. J. Mathar, Apr 05 2009
STATUS
approved