A069798 Primes whose digit reversal is a nontrivial power.

23, 61, 163, 487, 521, 691, 821, 1297, 1861, 4201, 4441, 4483, 5209, 5227, 9049, 9631, 12391, 14437, 16141, 16987, 61483, 63211, 65707, 65899, 67057, 69481, 92767, 94273, 96979, 106303, 108061, 123031, 123373, 125329, 127291, 129643, 142771, 146857, 148249

Offset: 1

Author

Amarnath Murthy, Apr 09 2002

Keywords

• base
• nonn

Examples

			691 is in the sequence because it is prime and its reversal, 196, is a power (greater than one) of 14.
		

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..14573

Crossrefs

Cf. A007488, A067194.

Programs

Mathematica

f[n_] := Block[{a, p = ToExpression[ StringReverse[ ToString[ Prime[n]]]]}, Log[ Apply[ Times, Transpose[ FactorInteger[p]][[1]]], p]]; Prime[ Select[ Range[10^5], IntegerQ[ f[ # ]] && f[ # ] > 1 &]]

PARI

lista(nn) = {forprime(p=2, nn, if (ispower(subst(Polrev(digits(p)), x, 10)), print1(p, ", ")););} \\ Michel Marcus, Jun 03 2016

Extensions

Edited, corrected and extended by Robert G. Wilson v, Apr 15 2002

Missing terms a(4), a(24), and a(26) added by Chai Wah Wu, Jun 02 2016