login
a(1)=1, a(n) = (a(n-1) + n) XOR n.
2

%I #14 Nov 26 2024 15:18:11

%S 1,1,7,15,17,17,31,47,49,49,55,79,81,81,111,111,145,177,215,255,257,

%T 257,271,319,321,321,327,383,385,385,447,511,513,513,519,527,529,529,

%U 543,623,689,753,823,847,849,849,943,1007,1041,1137,1175,1279,1281,1281

%N a(1)=1, a(n) = (a(n-1) + n) XOR n.

%H Paolo Xausa, <a href="/A237054/b237054.txt">Table of n, a(n) for n = 1..10000</a>

%F a(1)=1, then a(n) = (a(n-1) + n) XOR n, where XOR is the bitwise exclusive-OR operator.

%t Module[{n = 1}, NestList[BitXor[++n, # + n] &, 1, 100]] (* _Paolo Xausa_, Nov 26 2024 *)

%o (Python)

%o a=1

%o for n in range(2, 77):

%o print(a, end=', ')

%o a = (a+n) ^ n

%Y Cf. A182389, A182242.

%K nonn,easy

%O 1,3

%A _Alex Ratushnyak_, Feb 03 2014