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A203622
a(n) = (a(n-1) OR a(n-2)) XOR n.
0
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
0,3
COMMENTS
Indices of zeros: 2^(2x)-1, e.g. 0, 3, 15, 63, 255.
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.
PROG
(Python)
prpr = 0
prev = 1
for n in range(2, 77):
current = (prev | prpr) ^ n
print(prpr, end=', ')
prpr = prev
prev = current
CROSSREFS
Cf. A182560.
Sequence in context: A021769 A200119 A291943 * A201571 A010600 A175918
KEYWORD
nonn,base,easy
AUTHOR
Alex Ratushnyak, May 06 2012
STATUS
approved