A145750 - OEIS

A145750

Primes which become emirps when rotated by 180 degrees on a digital clock display.

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

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

The sequence contains all bemirps A048895.

Subsequence of A057770. [R. J. Mathar, Apr 05 2009]

LINKS

Table of n, a(n) for n=1..35.

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

Adjacent sequences: A145747 A145748 A145749 * A145751 A145752 A145753

KEYWORD

nonn,base

AUTHOR

Lekraj Beedassy, Apr 04 2009

EXTENSIONS

1109 removed, 6011 inserted etc. by R. J. Mathar, Apr 05 2009

STATUS

approved