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

Author

Rémy Sigrist, Feb 08 2021

Keywords

• nonn
• look
• base

Comments

All terms belong to A075926.

Examples

			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.
		

Links

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

Crossrefs

Cf. A075926, A261283.

Programs

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) }

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.