A209620 Emirps that become their own reversals when rotated through 180 degrees (including on calculator display).

1021, 1151, 1181, 1201, 1511, 1811, 10151, 11551, 15101, 15511, 100511, 101281, 102181, 102551, 105211, 105251, 108881, 110051, 110221, 110281, 110881, 111211, 111821, 112111, 112181, 112501, 115001, 115021, 118081, 120121, 120511, 121021, 121151, 122011

Offset: 1

Author

Lekraj Beedassy, Mar 21 2012

Keywords

• nonn
• base

Comments

Such emirps have end digits 1 and use only digits 0, 1, 2, 5, 8, and the sequence naturally includes A155512, the emirps with only digits 0 and 1.

Examples

			1181 of this sequence, for instance, belongs to the emirp pair (1181, 1811), where each member is a 180-degree rotation of the other; similarly for the term 112501 of this sequence, that belongs to the emirp pair (105211, 112501) and which, displayed on a calculator and turned upside-down, becomes its own reversal.
		

Crossrefs

Cf. A006567.

Programs

Mathematica

t1 = {0, 1, 2, 5, 8}; okQ[n_] := Module[{d = IntegerDigits[n], r}, r = Reverse[d];  r != d && Complement[d, t1] == {} && PrimeQ[FromDigits[r]]]; Select[Prime[Range[100000]], okQ] (* T. D. Noe, Apr 24 2012 *)