A178729 - OEIS

%I #27 Jun 30 2022 08:39:33

%S 0,2,4,10,8,10,20,18,16,18,20,42,40,42,36,34,32,34,36,42,40,42,84,82,

%T 80,82,84,74,72,74,68,66,64,66,68,74,72,74,84,82,80,82,84,170,168,170,

%U 164,162,160,162,164,170,168,170,148,146,144,146,148,138,136,138,132,130

%N a(n) = n XOR 3n, where XOR is bitwise XOR.

%H Vincenzo Librandi, <a href="/A178729/b178729.txt">Table of n, a(n) for n = 0..5000</a>

%F a(n) = A005351(n) XOR A005352(n) (conjectured).

%F a(n) = 2 * A184617(n). - _Alois P. Heinz_, Jul 21 2017

%t f[n_] := BitXor[n, 3 n]; Array[f, 70, 0] (* _Robert G. Wilson v_, Jun 09 2010 *)

%o (PARI) a(n) = bitxor(n, 3*n); \\ _Michel Marcus_, Jul 11 2017

%o (Magma) [BitwiseXor(n, 3*n): n in [0..80]]; // _Vincenzo Librandi_, Jul 11 2017

%o (Python)

%o def A178729(n): return n^ 3*n # _Chai Wah Wu_, Jun 29 2022

%Y Cf. A048724, A048725, A178731, A178732, A178733, A178734, A178735, A178736. - _Robert G. Wilson v_, Jun 09 2010

%Y Cf. A184617.

%K nonn

%O 0,2

%A _Dmitry Kamenetsky_, Jun 08 2010

%E a(30) onwards from _Robert G. Wilson v_, Jun 09 2010