A341273 If A261283(n) = 0, then a(n) = n, otherwise a(n) is obtained by flipping the A261283(n)-th rightmost bit in the binary expansion of n.

0, 0, 0, 7, 0, 7, 7, 7, 0, 25, 42, 75, 76, 45, 30, 7, 0, 25, 82, 51, 52, 85, 30, 7, 25, 25, 30, 25, 30, 25, 30, 30, 0, 97, 42, 51, 52, 45, 102, 7, 42, 45, 42, 42, 45, 45, 42, 45, 52, 51, 51, 51, 52, 52, 52, 51, 120, 25, 42, 51, 52, 45, 30, 127, 0, 97, 82, 75

Offset

0,4

Comments

All terms belong to A075926.

Links

Rémy Sigrist, Table of n, a(n) for n = 0..32768

Formula

A261283(a(n)) = 0.

a(a(n)) = a(n).

a(n) = n iff n belongs to A075926.

a(2^k) = 0 for any k >= 0.

Example

For n = 7:
- A261283(7) = 0,
- so a(7) = 7.
For n = 43:
- A261283(43) = 1,
- so a(43) is obtained by flipping the rightmost binary digit in 43,
- a(43) = 42.

Prog

(PARI) a(n) = { my (m=n, x=0); while (m, my (v=valuation(m, 2)); x=bitxor(x, v+1); m-=2^v); if (x, bitxor(n, 2^(x-1)), n) }

Crossrefs

Cf. A075926, A261283.

Sequence in context: A335727 A158857 A255727 * A011438 A321022 A216185

Adjacent sequences: A341270 A341271 A341272 * A341274 A341275 A341276

Keyword

nonn,look,base

Author

Rémy Sigrist, Feb 08 2021

Status

approved