A338242 a(n) = -A338241(2*n) for any n >= 0.

0, 1, 2, 3, 4, 8, 6, 7, 5, 9, 10, 11, 12, 13, 26, 24, 25, 23, 18, 19, 20, 21, 22, 17, 15, 16, 14, 27, 28, 29, 30, 31, 35, 33, 34, 32, 36, 37, 38, 39, 40, 80, 78, 79, 77, 72, 73, 74, 75, 76, 71, 69, 70, 68, 54, 55, 56, 57, 58, 62, 60, 61, 59, 63, 64, 65, 66, 67

Offset: 0

Author

Rémy Sigrist, Oct 18 2020

Keywords

• nonn

Comments

This sequence is a self-inverse permutation of the nonnegative integers.

Examples

			a(7) = -A338241(14) = 7.
		

Links

• Rémy Sigrist, Table of n, a(n) for n = 0..6560
• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A338241, A338243.

Programs

PARI

b(n) = { if (n==0, return (0), my (d=n%3, m=n\3); if (d==0, 3*b(m), d==1, 1-3*b(m), 3*b(m)-1)) }
a(n) = -b(2*n)