A109019 Numbers whose digit reversal is different and has the same number of prime factors (with multiplicity).

13, 15, 17, 26, 31, 37, 39, 49, 51, 58, 62, 71, 73, 79, 85, 93, 94, 97, 107, 113, 115, 117, 122, 123, 126, 129, 143, 147, 149, 155, 157, 158, 159, 165, 167, 169, 177, 178, 179, 183, 185, 187, 199, 203, 205, 221, 225, 226, 244, 246, 265, 270, 285, 286, 289, 290

Offset: 1

Author

Jonathan Vos Post, Jun 16 2005

Keywords

• nonn
• base

Comments

Ray Chandler has coauthorship credit for this sequence.

Links

• Eric Weisstein's World of Mathematics, Almost Prime.
• Eric Weisstein's World of Mathematics, Emirp.
• Eric Weisstein's World of Mathematics, Emirpimes.

Crossrefs

Cf. A006567, A097393, A109018, A109023-A109031.

Programs

Mathematica

Select[Range@1000, ! PalindromeQ@# && Differences@PrimeOmega@{#,IntegerReverse@#} == {0} &] (* Hans Rudolf Widmer, Jun 03 2022 *)

Formula

{A006567} U {A097393} U {A109023} U {A109024} U ... U {A109031} U ...

Extensions

More terms from Stefan Steinerberger, Jun 16 2007