A380992 Powers of two which produce a prime number when their digits are reversed.

2, 16, 32, 128, 1024, 131072, 16777216, 137438953472, 35184372088832, 36028797018963968, 1180591620717411303424, 151115727451828646838272, 162259276829213363391578010288128, 174224571863520493293247799005065324265472, 1427247692705959881058285969449495136382746624

Offset

1,1

Comments

A057708 is the main entry for this question. - N. J. A. Sloane, Feb 28 2025

Links

Table of n, a(n) for n=1..15.

Formula

a(n) = 2^A057708(n). - Pontus von Brömssen, Feb 11 2025

Example

The digits of 1024 (2^10) reverse to form the prime number 4201.

Mathematica

Select[2^Range[200], PrimeQ[IntegerReverse[#]]&] (* James C. McMahon, Feb 28 2025 *)

Crossrefs

Cf. A057708.

Sequence in context: A344016 A279034 A120069 * A018975 A012696 A012392

Adjacent sequences: A380989 A380990 A380991 * A380993 A380994 A380995

Keyword

nonn,base

Author

Paul Duckett, Feb 11 2025

Status

approved