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A182560
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a(n) = (a(n-1) AND a(n-2)) XOR n.
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3
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0, 1, 2, 3, 6, 7, 0, 7, 8, 9, 2, 11, 14, 7, 8, 15, 24, 25, 10, 27, 30, 15, 24, 31, 0, 25, 26, 3, 30, 31, 0, 31, 32, 33, 2, 35, 38, 7, 32, 39, 8, 41, 34, 11, 46, 39, 8, 47, 56, 25, 42, 59, 30, 47, 56, 31, 32, 57, 26, 35, 62, 31, 32, 63, 96, 97, 34, 99, 102, 39, 96, 103
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,3
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COMMENTS
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Conjecture: sequence contains infinitely many zeros.
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LINKS
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Eric Weisstein's World of Mathematics, AND
Eric Weisstein's World of Mathematics, XOR
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FORMULA
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a(0)=0, a(1)=1, a(n) = (a(n-1) AND a(n-2)) XOR n, where AND is the bitwise AND operator, XOR is the bitwise exclusive-or operator.
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MATHEMATICA
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nxt[{n_, a_, b_}]:={n+1, b, BitXor[BitAnd[a, b], n+1]}; NestList[nxt, {1, 0, 1}, 80][[All, 2]] (* Harvey P. Dale, Jan 01 2019 *)
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PROG
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(Python)
prpr = 0
prev = 1
for n in range(2, 55):
. current = (prev & prpr) ^ n
. print prpr,
. prpr = prev
. prev = current
(Haskell)
import Data.Bits ((.&.), xor)
a182560 n = a182560_list !! n
a182560_list = 0 : 1 : 2 : zipWith xor [3..]
(tail $ zipWith (.&.) a182560_list $ tail a182560_list) :: [Integer]
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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STATUS
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approved
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