A125308 -id:A125308 - cp's OEIS frontend

A007628 Reflectable emirps.

13, 31, 113, 311, 1031, 1033, 1103, 1181, 1301, 1381, 1811, 1831, 3011, 3083, 3301, 3803, 10333, 11003, 11083, 11833, 18013, 18133, 18803, 30011, 30881, 31033, 31081, 31183, 33013, 33181, 33301, 33811, 38011, 38113

Offset: 1

N. J. A. Sloane, Mira Bernstein, Robert G. Wilson v

Subsequence of A125308, the reflectable primes. - Reinhard Zumkeller, Jul 16 2014

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
C. W. Trigg, "Reflective Primes", J. Rec. Math., 15 (1983), 251-256.

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
Prime Glossary, Reflectable prime
C. W. Trigg, Reflectable primes, J. Recreational Mathematics 15.4 (1983), 253. (Annotated scanned copy)

Cf. A003684, A006567, A046732, A048051, A048052, A048053, A048054, A048895.

Cf. A010051, A004086, A125308.

a007628 n = a007628_list !! (n-1)
a007628_list = filter f a125308_list where
   f p = a010051' q == 1 && q /= p  where q = a004086 p
-- Reinhard Zumkeller, Jul 16 2014

Missing 1811 inserted by Reinhard Zumkeller, Jul 16 2014

A178318 Primes which remain prime after reflection across a vertical line through the middle of the number (numbers are written as digital clock style numerals).

Original entry on oeis.org

2, 5, 11, 101, 181, 1051, 1181, 1201, 1811, 10151, 11251, 11551, 12101, 12211, 12511, 15121, 18181, 100151, 100501, 101501, 101581, 102001, 102101, 102181, 102551, 105211, 105251, 108881, 110051, 110581, 110881, 111521, 111581, 115021, 115201

Offset: 1

David Nacin, May 24 2010

Apart from first two terms: subsequence of A208259. - Reinhard Zumkeller, Jul 16 2014

			For example 1051 becomes 1201 under this reflection and since these are both prime, these number are part of the sequence. Note that a number must be composed only of the digits 0,1,2,5,8 to qualify.

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Cf. A125308, A178317.

Cf. A010051, A004086, A208259, A062332.

import Data.List (intersect, genericIndex)
a178318 n = a178318_list !! (n-1)
a178318_list = 2 : 5 : filter f a062332_list where
   f p = null (show p `intersect` "34679") && a010051' (r 0 p) == 1
   r y 0 = y
   r y x = r (10 * y + genericIndex [0,1,5,0,0,2,0,0,8,0] d) x'
             where (x', d) = divMod x 10
-- Reinhard Zumkeller, Jul 16 2014

cp's OEIS Frontend

A007628 Reflectable emirps.

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