A267105 Permutation of natural numbers: a(1) = 1, a(A080147(n)) = 1+(2*a(n)), a(A080148(n)) = 2*a(n).

1, 2, 3, 4, 6, 5, 7, 8, 12, 9, 10, 13, 11, 14, 16, 15, 24, 17, 18, 20, 25, 26, 22, 19, 21, 27, 28, 32, 23, 29, 30, 48, 33, 34, 31, 36, 49, 40, 50, 35, 52, 37, 44, 41, 51, 38, 42, 54, 56, 53, 45, 64, 39, 46, 43, 58, 55, 60, 57, 65, 96, 47, 66, 68, 59, 61, 62, 97, 72, 67, 69, 98, 80, 63, 100, 70, 73, 99, 81, 101, 104, 71, 74

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..10001

Index entries for sequences that are permutations of the natural numbers

Formula

a(1) = 1; and for n > 1, if prime(n) mod 4 = 1, then a(n) = 1 + 2*a(A267097(n)), otherwise a(n) = 2*a(A267098(n)).

Prog

(Scheme, with memoization-macro definec)
(definec (A267105 n) (cond ((<= n 1) n) ((= 1 (modulo (A000040 n) 4)) (+ 1 (* 2 (A267105 (A267097 n))))) (else (* 2 (A267105 (A267098 n))))))

Crossrefs

Inverse: A267106.

Cf. A000040, A002144, A002145, A080147, A080148, A267097, A267098.

Cf. also A267107.

Sequence in context: A361482 A257683 A343152 * A080542 A330090 A072758

Adjacent sequences: A267102 A267103 A267104 * A267106 A267107 A267108

Keyword

nonn

Author

Antti Karttunen, Feb 01 2016

Status

approved