A182509 a(0)=0, a(1)=1, a(n)=(a(n-1) XOR n) + a(n-2).

0, 1, 3, 1, 8, 14, 16, 37, 61, 89, 144, 244, 392, 633, 1023, 1641, 2680, 4306, 6968, 11261, 18209, 29489, 47688, 77200, 124880, 202073, 326931, 528993, 855952, 1384942, 2240896, 3625869, 5866797, 9492633, 15359464, 24852068, 40211496, 65063537, 105275007

Offset

0,3

Comments

Terms with indices 6k+1, 6k+2, 6k+3 are odd, all other terms are even.

Links

Table of n, a(n) for n=0..38.

Formula

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

Prog

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

Crossrefs

Sequence in context: A131202 A287987 A067955 * A049965 A221736 A077108

Adjacent sequences: A182506 A182507 A182508 * A182510 A182511 A182512

Keyword

nonn,base,easy

Author

Alex Ratushnyak, May 03 2012

Status

approved