A264989 Self-inverse permutation of nonnegative integers: a(n) = (A264987(n)-1) / 2.

0, 1, 2, 5, 4, 3, 6, 7, 11, 14, 16, 8, 17, 13, 9, 18, 10, 12, 15, 19, 20, 47, 22, 29, 56, 34, 38, 41, 43, 23, 50, 49, 32, 59, 25, 35, 44, 52, 26, 53, 40, 27, 54, 28, 36, 45, 55, 21, 48, 31, 30, 57, 37, 39, 42, 46, 24, 51, 58, 33, 60, 61, 101, 128, 142, 74, 155, 67, 83, 164, 88, 110, 137, 169, 65, 146, 103, 92, 173, 115, 119, 122

Offset

0,3

Links

Antti Karttunen, Table of n, a(n) for n = 0..4921

Index entries for sequences that are permutations of the natural numbers

Formula

a(n) = (A264987(n)-1) / 2.

a(n) = (1/2) * (A263272((2*n)+1) - 1).

a(n) = (1/4) * (A263273(4n + 2) - 2).

Prog

(Scheme, two alternative definitions)
(define (A264989 n) (/ (- (A264987 n) 1) 2))
(define (A264989 n) (/ (- (A263273 (A016825 n)) 2) 4))

Crossrefs

Cf. A016825, A263272, A263273, A264987, A264991, A264992.

Cf. also A264985.

Sequence in context: A275105 A128173 A265362 * A328625 A060125 A265361

Adjacent sequences: A264986 A264987 A264988 * A264990 A264991 A264992

Keyword

nonn

Author

Antti Karttunen, Dec 05 2015

Status

approved