|
%I #14 May 21 2024 01:17:28
%S 10,40,75,88,300,500,640,4100,8300
%N Numbers m such that a^t + b^t + c^t + ... is prime, where a*b*c* ... is the prime factorization of m with multiplicity and t is the reversal of m.
%C 44800, 93950, 98000, 200000, 220000, 260000, and 361000 are also terms. - _Michael S. Branicky_, May 20 2024
%e a(3)=75 because 75=3*5^2 and 75 reversed is 57 and 3^57 + 5^57 + 5^57 = 13877787807816026798194477932746894440813, a prime.
%t 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 *)
%Y Cf. A082813.
%K base,more,nonn
%O 1,1
%A _Jason Earls_, Jun 27 2005
%E 300, 500, 640 from _Robert G. Wilson v_, Jun 27 2005
%E 4100 and 8300 from _Hans Havermann_, Jun 29 2005
|
