%I A070008
%S A070008 2,4,8,15,16,32,39,42,45,55,64,75,84,87,114,117,126,128,135,168,170,
%T A070008 183,225,228,247,252,256,258,261,275,294,295,336,340,342,351,375,378,
%U A070008 405,410,456,504,507,512,516,549,583,588,605,672,675,680,684,756,774
%N A070008 Arithmetical mean of distinct primes dividing n is a power of 2 (n=powers
of 2 are not left out).
%e A070008 n=9189=3.1021, mean=(3+1021)/2=512.
%t A070008 ffi[x_] := Flatten[FactorInteger[x]] lf[x_] := Length[FactorInteger[x]]
ba[x_] := Table[Part[ffi[x], 2*w-1], {w, 1, lf[x]}] Do[s=Apply[Plus,
ba[n]]/lf[n]; If[IntegerQ[Log[2, s]], Print[{n, s}]], {n, 2, 10000}]
%Y A070008 Cf. A070005-A070007, A008472, A001414.
%Y A070008 Sequence in context: A076351 A140117 A039743 this_sequence A033623 A094398
A026474
%Y A070008 Adjacent sequences: A070005 A070006 A070007 this_sequence A070009 A070010
A070011
%K A070008 nonn
%O A070008 1,1
%A A070008 Labos E. (labos(AT)ana.sote.hu), Apr 11 2002
|