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A318468 a(n) = 2*n AND A000203(n), where AND is bitwise-and (A004198) and A000203 = sum of divisors. 13


%S 0,0,4,0,2,12,8,0,0,16,4,24,10,24,24,0,2,36,4,40,32,36,8,48,18,32,32,

%T 56,26,8,32,0,0,4,0,72,2,12,8,80,2,64,4,80,74,72,16,96,32,68,64,96,34,

%U 104,72,112,80,80,52,40,58,96,104,0,0,128,4,8,0,128,8,128,2,16,20,136,0,136,16,160,32,36,4,160,40,132,40,176,18,160,48

%N a(n) = 2*n AND A000203(n), where AND is bitwise-and (A004198) and A000203 = sum of divisors.

%H Antti Karttunen, <a href="/A318468/b318468.txt">Table of n, a(n) for n = 1..65537</a>

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

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

%F a(n) = A004198(2*n, A000203(n)).

%F a(n) = A224880(n) - A318466(n) = (A224880(n)-A318467(n))/2.

%t Array[BitAnd[2 #, DivisorSigma[1, #]] &, 91] (* _Michael De Vlieger_, Apr 21 2019 *)

%o (PARI) A318468(n) = bitand(2*n,sigma(n));

%Y Cf. A000203, A003987, A318466, A318467.

%Y Cf. also A318458.

%K nonn,base

%O 1,3

%A _Antti Karttunen_, Aug 26 2018

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Last modified December 5 10:45 EST 2019. Contains 329751 sequences. (Running on oeis4.)