A338824 - OEIS

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A338824

Lexicographically earliest sequence of nonnegative integers such that for any distinct m and n, a(m) OR a(m+1) <> a(n) OR a(n+1) (where OR denotes the bitwise OR operator).

0, 0, 1, 2, 0, 4, 1, 6, 0, 8, 1, 10, 0, 12, 1, 14, 0, 16, 1, 18, 0, 20, 1, 22, 0, 24, 1, 26, 0, 28, 1, 30, 0, 32, 1, 34, 0, 36, 1, 38, 0, 40, 1, 42, 0, 44, 1, 46, 0, 48, 1, 50, 0, 52, 1, 54, 0, 56, 1, 58, 0, 60, 1, 62, 0, 64, 1, 66, 0, 68, 1, 70, 0, 72, 1, 74

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,4

LINKS

Table of n, a(n) for n=1..76.

Rémy Sigrist, C program for A338824

FORMULA

a(2*n) = 2*n-2 for any n > 0.

a(4*n+1) = 0 for any n >= 0.

a(4*n+3) = 1 for any n >= 0.

a(n) OR a(n+1) = A116966(n-2) for any n > 1.

EXAMPLE

The first terms, alongside a(n) OR a(n+1), are:

n a(n) a(n) OR a(n+1)

-- ---- --------------

1 0 0

2 0 1

3 1 3

4 2 2

5 0 4

6 4 5

7 1 7

8 6 6

9 0 8

10 8 9

11 1 11

12 10 10

MATHEMATICA

Block[{a = {0, 0}, b = {0}}, Do[Block[{k = 0, m}, While[! FreeQ[b, Set[m, BitOr @@ {a[[-1]], k}]], k++]; AppendTo[a, k]; AppendTo[b, m]], {i, 3, 76}]; a] (* Michael De Vlieger, Nov 12 2020 *)

PROG

CROSSREFS

Cf. A116966, A338823.

Sequence in context: A176910 A243981 A369657 * A056737 A289144 A350576

Adjacent sequences: A338821 A338822 A338823 * A338825 A338826 A338827

KEYWORD

nonn,base

AUTHOR

Rémy Sigrist, Nov 11 2020

STATUS

approved