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%I #15 Mar 22 2026 23:30:59
%S 1,62,742,7913,81580,830966,8413600,84902275,854911636,8595788628,
%T 86336979626,866510090881,8691542224682,87141123346483,
%U 873360370035565,8750606225568966,87655681172037954,877883602836107139,8790682286910283101,88013238064412080119,881093550115629692808
%N a(n) is the number of n-digit numbers that are not powers of primes.
%F Limit_{n->oo} a(n)/a(n-1) = 10.
%F a(n) = A052268(n) - A304520(n) for n > 1.
%t a[n_]:=Module[{k=0},For[i=10^(n-1),i<=10^n-1,i++,If[Length[FactorInteger[i]]>1,k++]]; k]; Array[a,7]
%Y Cf. A024619, A052268, A304520.
%K nonn,base
%O 1,2
%A _Stefano Spezia_, Mar 15 2026