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A108777 Numbers n such that a^t + b^t + c^t + ... is prime, where a*b*c* ... is the prime factorization of n with multiplicity and t is the reversal of n. 0
10, 40, 75, 88, 300, 500, 640, 4100, 8300 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

a(3)=75 because 75=3*5^2 and 75 reversed is 57 and 3^57 + 5^57 + 5^57 = 13877787807816026798194477932746894440813, a prime.

MATHEMATICA

fQ[n_] := PrimeQ[Plus @@ (Flatten[ Table[ #[[1]], {#[[2]]}] & /@ FactorInteger[n]]^FromDigits[ Reverse[ IntegerDigits[ n]] ])]; Do[ If[ fQ[n], Print[n]], {n, 2200}] (* Robert G. Wilson v, Jun 28 2005 *)

CROSSREFS

Cf. A082813.

Sequence in context: A187205 A104045 A102546 * A000132 A306830 A305131

Adjacent sequences:  A108774 A108775 A108776 * A108778 A108779 A108780

KEYWORD

base,more,nonn

AUTHOR

Jason Earls, Jun 27 2005

EXTENSIONS

300, 500, 640 from Robert G. Wilson v, Jun 27 2005

4100 and 8300 from Hans Havermann, Jun 29 2005

STATUS

approved

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Last modified May 22 21:50 EDT 2019. Contains 323504 sequences. (Running on oeis4.)