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A069798 Primes whose digit reversal is a nontrivial power. 3
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
691 is in the sequence because it is prime and its reversal, 196, is a power (greater than one) of 14.
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 &]]
PROG
(PARI) lista(nn) = {forprime(p=2, nn, if (ispower(subst(Polrev(digits(p)), x, 10)), print1(p, ", ")); ); } \\ Michel Marcus, Jun 03 2016
CROSSREFS
Sequence in context: A215166 A141870 A115685 * A067194 A355984 A355985
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Apr 09 2002
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
STATUS
approved

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Last modified November 29 03:03 EST 2023. Contains 367422 sequences. (Running on oeis4.)