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A327187 For any n >= 0: consider the different ways to split the binary representation of n into two (possibly empty) parts, say with value x and y; a(n) is the least possible value of x XOR y (where XOR denotes the bitwise XOR operator). 3
0, 1, 1, 0, 1, 0, 3, 2, 1, 0, 0, 1, 3, 2, 1, 0, 1, 0, 0, 1, 5, 4, 4, 5, 3, 2, 1, 0, 7, 6, 5, 4, 1, 0, 0, 1, 0, 1, 2, 3, 5, 4, 7, 6, 1, 0, 3, 2, 3, 2, 1, 0, 2, 3, 0, 1, 7, 6, 5, 4, 3, 2, 1, 0, 1, 0, 0, 1, 0, 1, 2, 3, 9, 8, 8, 9, 8, 9, 10, 11, 5, 4, 7, 6, 1, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,7

LINKS

Rémy Sigrist, Table of n, a(n) for n = 0..8192

FORMULA

a(n) = 0 iff n = 0 or n belongs to A175468.

EXAMPLE

For n=42:

- the binary representation of 42 is "101010",

- there are 7 ways to split it:

   - "" and "101010": x=0 and y=42: 0 XOR 42 = 42,

   - "1" and "01010": x=1 and y=10: 1 XOR 10 = 11,

   - "10" and "1010": x=2 and y=10: 2 XOR 10 = 8,

   - "101" and "010": x=5 and y=2: 5 XOR 2 = 7,

   - "1010" and "10": x=10 and y=2: 10 XOR 2 = 8,

   - "10101" and "0": x=21 and y=0: 21 XOR 0 = 21,

   - "101010" and "": x=42 and y=0: 42 XOR 0 = 42,

- hence a(42) = 7.

PROG

(PARI) a(n) = my (v=oo, b=binary(n)); for (w=0, #b, v=min(v, bitxor(fromdigits(b[1..w], 2), fromdigits(b[w+1..#b], 2)))); v

CROSSREFS

See A327186 for other variants.

Cf. A175468.

Sequence in context: A058257 A330959 A083199 * A274537 A305234 A021761

Adjacent sequences:  A327184 A327185 A327186 * A327188 A327189 A327190

KEYWORD

nonn,look,base

AUTHOR

Rémy Sigrist, Aug 25 2019

STATUS

approved

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Last modified November 30 20:17 EST 2021. Contains 349425 sequences. (Running on oeis4.)