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A330955
For any n >= 0: consider all pairs of numbers (x, y) whose binary representations can be interleaved (or shuffled) to produce the binary representation of n (possibly with leading zeros); a(n) is the greatest possible value of x AND y (where AND denotes the bitwise AND operator).
2
0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 2, 2, 2, 2, 2, 3, 0, 1, 2, 2, 2, 2, 2, 3, 0, 1, 2, 3, 2, 2, 2, 3, 0, 1, 2, 2, 4, 4, 4, 4, 4, 4, 4, 5, 4, 5, 4, 5, 4, 4, 4, 5, 4, 5, 6, 6, 4, 4, 6, 6, 6, 6, 6, 7, 0, 1, 2, 2, 4, 4, 4, 4, 4, 4, 4, 5, 4, 5, 4, 5, 4, 4, 4, 5, 4, 5, 6
OFFSET
0,11
EXAMPLE
For n = 5:
- the binary representation of 5 is "101",
- the possible values for (x, y), restricted to x >= y without loss of generality, are:
bin(5) x y x AND y
------- - - -------
"101" 5 0 0
"1/01" 1 1 1
"10/1" 2 1 0
"1/0/1" 3 0 0
- hence a(5) = 1.
PROG
(C) See Links section.
CROSSREFS
See A330925 for similar sequences.
Cf. A327188.
Sequence in context: A319991 A323275 A139514 * A330956 A190617 A068323
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Jan 04 2020
STATUS
approved