%I #7 Mar 05 2019 18:19:52

%S 0,0,0,1,0,1,0,1,6,0,0,1,0,1,8,9,0,1,0,1,16,1,0,1,0,1,10,1,0,1,0,1,0,

%T 1,20,9,0,1,66,1,0,1,0,1,6,1,0,1,0,0,2,1,0,1,36,1,258,1,0,1,0,1,6,41,

%U 0,1,0,1,0,1,0,17,0,1,16,1,32,1,0,1,10,1,0,1,132,1,1026,1,0,33,72,1,0,1,256,25,0,0,66,17,0,1,0,1,34

%N a(1) = 0; for n > 1, a(n) = A318458(A156552(n)).

%H Antti Karttunen, <a href="/A324398/b324398.txt">Table of n, a(n) for n = 1..4473</a>

%H <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>

%H <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>

%H <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>

%F a(1) = 0; for n > 1, a(n) = A318458(A156552(n)).

%F a(n) = A156552(n) AND (A323243(n) - A156552(n)).

%o (PARI)

%o A064989(n) = {my(f); f = factor(n); if((n>1 && f[1,1]==2), f[1,2] = 0); for (i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f)};

%o A156552(n) = if(1==n, 0, if(!(n%2), 1+(2*A156552(n/2)), 2*A156552(A064989(n))));

%o A318458(n) = bitand(n, sigma(n)-n);

%o A324398(n) = if(1==n,0,A318458(A156552(n)));

%Y Cf. A000203, A156552, A318458, A323243, A323244, A324396, A324397.

%K nonn

%O 1,9

%A _Antti Karttunen_, Mar 05 2019