cp's OEIS Frontend

A108697 Numbers n such that a^r + b^r + c^r + ... is prime, where a*b*c* ... is the prime factorization of n and r is the product of the nonzero digits of n.

%I A108697 #6 Dec 15 2017 17:36:50
%S A108697 10,11,12,14,22,40,54,101,122,136,250,261,300,328,500,539,704,720,850,
%T A108697 1001,1016,1020,1110,1112,1140,1210,1402,2121,2211,2220,2254,2400,
%U A108697 3081,3114,3311,4011,4100,4180,4510,6231,9093,10110,10111,10112,10203,10216
%N A108697 Numbers n such that a^r + b^r + c^r + ... is prime, where a*b*c* ... is the prime factorization of n and r is the product of the nonzero digits of n.
%C A108697 Of the terms shown, 9093 generates the largest prime, 3^243+7^243+433^243, which has 641 digits. - _David Wasserman_, May 22 2008
%C A108697 a(74) = 15273. Of the first 74 terms, a(72) = 14464 generates the largest prime, 7*2^384+113^384, which has 789 digits. - _David Wasserman_, May 22 2008
%e A108697 22 is in the sequence because 22 = 2*11 and 2^(2*2) + 11^(2*2) = 14657, a prime.
%Y A108697 Cf. A051801, A082813.
%Y A108697 A020449 is a subsequence.
%K A108697 base,less,nonn
%O A108697 1,1
%A A108697 _Jason Earls_, Jun 19 2005
%E A108697 More terms from _David Wasserman_, May 22 2008