A118012 a(n) = 4*A117384(n) - n; a self-inverse permutation of the natural numbers.

3, 6, 1, 8, 11, 2, 13, 4, 15, 18, 5, 20, 7, 22, 9, 24, 27, 10, 29, 12, 31, 14, 33, 16, 35, 38, 17, 40, 19, 42, 21, 44, 23, 46, 25, 48, 51, 26, 53, 28, 55, 30, 57, 32, 59, 34, 61, 36, 63, 66, 37, 68, 39, 70, 41, 72, 43, 74, 45, 76, 47, 78, 49, 80, 83, 50, 85, 52, 87, 54, 89, 56

Offset: 1

Author

Paul D. Hanna, Apr 10 2006

Keywords

• nonn

Comments

A117384 is defined by A117384(n) = A117384(k) when k = 4*A117384(n) - n. A001614 is the Connell sequence generated as: 1 odd, 2 even, 3 odd, .. and A118011 is the complement of A001614.

Crossrefs

Cf. A117384, A001614, A118011.

Formula

a(a(n)) = n; a(A118011(n)) = a(4*n - A001614(n)) = A001614(n).