A324820 - OEIS

%I #8 Mar 19 2019 23:00:48

%S 0,0,0,4,0,2,0,12,12,0,0,2,0,2,16,16,0,4,0,0,36,0,0,0,24,0,20,6,0,50,

%T 0,56,4,0,40,44,0,2,128,0,0,38,0,0,56,0,0,8,48,10,4,0,0,4,72,4,512,2,

%U 0,34,0,0,36,72,8,6,0,4,4,40,0,100,0,0,40,6,80,130,0,8,16,0,0,22,256,0,2048,8,0,90,128,4

%N Xor-Moebius transform of A324815.

%H Antti Karttunen, <a href="/A324820/b324820.txt">Table of n, a(n) for n = 1..10000</a> (based on Hans Havermann's factorization of A156552)

%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(p) = 0 for all primes p.

%o (PARI)

%o A156552(n) = {my(f = factor(n), p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res}; \\ From A156552 by _David A. Corneth_

%o A324815(n) = bitand(2*A156552(n),A323243(n)); \\ Needs code also from A323243.

%o A324820(n) = { my(v=0); fordiv(n, d, if(issquarefree(n/d), v=bitxor(v, A324815(d)))); (v); };

%Y Cf. A156552, A323243, A324815, A324821, A324878.

%K nonn

%O 1,4

%A _Antti Karttunen_, Mar 18 2019