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A318466 a(n) = 2*n OR A000203(n), where OR is bitwise-or (A003986) and A000203 = sum of divisors.

%I A318466 #15 Jul 10 2022 10:47:00
%S A318466 3,7,6,15,14,12,14,31,31,22,30,28,30,28,30,63,50,39,54,42,42,44,62,60,
%T A318466 63,62,62,56,62,124,62,127,114,118,118,91,110,124,126,90,122,116,126,
%U A318466 92,94,92,126,124,123,125,110,106,126,124,110,120,114,126,126,248,126,124,126,255,214,148,198,254,234,156,206
%N A318466 a(n) = 2*n OR A000203(n), where OR is bitwise-or (A003986) and A000203 = sum of divisors.
%H A318466 Antti Karttunen, <a href="/A318466/b318466.txt">Table of n, a(n) for n = 1..65537</a>
%H A318466 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%H A318466 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F A318466 a(n) = A003986(2*n, A000203(n)).
%F A318466 a(n) = A224880(n) - A318468(n).
%t A318466 Array[BitOr[2 #, DivisorSigma[1, #]] &, 71] (* _Michael De Vlieger_, Mar 30 2019 *)
%o A318466 (PARI) A318466(n) = bitor(2*n,sigma(n));
%o A318466 (Python)
%o A318466 from sympy import divisor_sigma
%o A318466 def A318466(n): return (n<<1)|int(divisor_sigma(n)) # _Chai Wah Wu_, Jul 10 2022
%Y A318466 Cf. A000203, A003986, A224880, A318467, A318468.
%Y A318466 Cf. also A318456.
%K A318466 nonn,look,base
%O A318466 1,1
%A A318466 _Antti Karttunen_, Aug 26 2018