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%I #9 Jan 21 2017 12:46:43
%S 15,20,21,28,35,39,44,48,51,52,55,65,69,85,91,92,95,108,112,115,116,
%T 129,135,141,145,159,164,172,188,189,205,208,209,215,221,225,235,236,
%U 245,249,259,268,272,295,297,299,305,309,315,316,320,325,329,339,341,365
%N Numbers such that the arithmetic mean of the squares of their prime factors (taken with multiplicity) is a prime.
%H Hieronymus Fischer, <a href="/A134617/b134617.txt">Table of n, a(n) for n = 1..10000</a>
%e a(2)=20, since 20=2*2*5 and (2^2+2^2+5^2)/3=33/3=11.
%t amspQ[n_]:=PrimeQ[Mean[Flatten[Table[#[[1]],#[[2]]]&/@FactorInteger[ n]]^2]]; Select[Range[400],amspQ] (* _Harvey P. Dale_, Jan 21 2017 *)
%Y Cf. A001597, A025475, A134333, A134344, A134376.
%Y Cf. A134600, A134602, A134605, A134608, A134613, A134619, A134621.
%K nonn
%O 1,1
%A _Hieronymus Fischer_, Nov 11 2007
%E Minor edits by the author, May 06 2013