%I #10 Jan 21 2020 18:22:35
%S 1,2,3,2,5,4,9,4,3,6,17,6,33,10,7,2,65,6,129,10,11,18,257,8,5,34,9,18,
%T 513,8,1025,4,19,66,13,4,2049,130,35,12,4097,12,8193,34,15,258,16385,
%U 6,9,10,67,66,32769,12,21,20,131,514,65537,14,131073,1026,27,4,37,20,262145,130,259,14,524289,8,1048577,2050,15
%N a(n) = A000005(A225546(n)), where A000005 gives the number of divisors of n.
%H Antti Karttunen, <a href="/A331309/b331309.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = A000005(A225546(n)).
%o (PARI)
%o A048675(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*2^primepi(f[k, 1]))/2; };
%o A331309(n) = if(1==n,1,my(f=factor(n),u=#binary(vecmax(f[, 2])),prods=vector(u,x,1),m=1,e); for(i=1,u,for(k=1,#f~, if(bitand(f[k,2],m),prods[i] *= f[k,1])); m<<=1); prod(i=1,u,1+A048675(prods[i])));
%Y Cf. A000005, A048675, A225546, A331287, A331308, A331591.
%K nonn
%O 1,2
%A _Antti Karttunen_, Jan 21 2020