A182537 a(0)=0, a(1)=1, a(n) = a(n-1) + (a(n-2) XOR n).

0, 1, 3, 5, 12, 12, 22, 33, 63, 103, 156, 264, 408, 669, 1075, 1733, 2792, 4540, 7350, 11877, 19207, 31095, 50312, 81384, 131704, 213097, 344779, 557885, 902676, 1460532, 2363198, 3823721, 6186887, 10010575, 16197492, 26208096, 42405552, 68613621, 111019147, 179632733

Offset

0,3

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Formula

a(0)=0, a(1)=1, a(n) = a(n-1) + (a(n-2) XOR n), where XOR is the bitwise exclusive-or operator.

Mathematica

nxt[{n_, a_, b_}]:={n+1, b, b+BitXor[a, n+1]}; NestList[nxt, {1, 0, 1}, 40][[All, 2]] (* Harvey P. Dale, Jul 02 2021 *)

Prog

(Python)
prpr, prev = 0, 1
for n in range(2, 99):
.  current = prev + (prpr ^ n)
.  print prpr,
.  prpr, prev = prev, current

Crossrefs

Cf. A182509, A182536.

Sequence in context: A361322 A037221 A379759 * A259309 A212061 A287570

Adjacent sequences: A182534 A182535 A182536 * A182538 A182539 A182540

Keyword

nonn,base,easy

Author

Alex Ratushnyak, May 04 2012

Status

approved