A203622 a(n) = (a(n-1) OR a(n-2)) XOR n.

0, 1, 3, 0, 7, 2, 1, 4, 13, 4, 7, 12, 3, 2, 13, 0, 29, 12, 15, 28, 11, 10, 29, 8, 5, 20, 15, 4, 19, 10, 5, 16, 53, 20, 23, 52, 19, 18, 53, 16, 29, 52, 23, 28, 51, 18, 29, 48, 13, 12, 63, 12, 11, 58, 13, 8, 53, 4, 15, 52, 3, 10, 53, 0, 117, 52, 55, 116, 51, 50, 117

Offset: 0

Author

Alex Ratushnyak, May 06 2012

Keywords

• nonn
• base
• easy

Comments

Indices of zeros: 2^(2x)-1, e.g. 0, 3, 15, 63, 255.

Crossrefs

Cf. A182560.

Programs

Python

prpr = 0
prev = 1
for n in range(2,77):
    current = (prev | prpr) ^ n
    print(prpr, end=',')
    prpr = prev
    prev = current

Formula

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