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A334076 a(n) = bitwise NOR of n and 2n.

%I A334076 #37 Apr 18 2020 17:09:53
%S A334076 0,0,1,0,3,0,1,0,7,4,1,0,3,0,1,0,15,12,9,8,3,0,1,0,7,4,1,0,3,0,1,0,31,
%T A334076 28,25,24,19,16,17,16,7,4,1,0,3,0,1,0,15,12,9,8,3,0,1,0,7,4,1,0,3,0,1,
%U A334076 0,63,60,57,56,51,48,49,48,39,36,33,32,35,32,33
%N A334076 a(n) = bitwise NOR of n and 2n.
%C A334076 Exactly all bits that are 0 in both parameters (but not a leading 0 of both) are set to 1 in the output of bitwise NOR.
%H A334076 Alois P. Heinz, <a href="/A334076/b334076.txt">Table of n, a(n) for n = 0..32767</a>
%H A334076 Wikipedia, <a href="https://en.wikipedia.org/wiki/Bitwise operation">Bitwise operation</a>
%F A334076 a(n) = 0 <=> n in { A247648 } union { 0 }.
%F A334076 a(n) = n-1 <=> n in { A000079 }.
%F A334076 a(n) = n/2 <=> n in { A125835 }.
%F A334076 a(n) = n*3/4 <=> n in { A141032 }.
%p A334076 a:= n-> Bits[Nor](n, 2*n):
%p A334076 seq(a(n), n=0..127);
%o A334076 (Python)
%o A334076 def A334076(n):
%o A334076     m = n|(2*n)
%o A334076     return 0 if n == 0 else 2**(len(bin(m))-2)-1-m # _Chai Wah Wu_, Apr 14 2020
%o A334076 (PARI) a(n) = my(x=bitor(n, 2*n)); bitneg(x, #binary(x)); \\ _Michel Marcus_, Apr 14 2020
%Y A334076 Cf. A000079, A048724, A125835, A141032, A163617, A213370, A247648.
%K A334076 nonn,look,base
%O A334076 0,5
%A A334076 _Alois P. Heinz_, Apr 13 2020