A269379 a(1) = 1; for n > 1, a(n) = A255127(A260738(n)+1, A260739(n)).

1, 3, 5, 9, 7, 15, 11, 21, 19, 27, 13, 33, 17, 39, 35, 45, 23, 51, 31, 57, 49, 63, 25, 69, 29, 75, 65, 81, 37, 87, 55, 93, 79, 99, 59, 105, 41, 111, 95, 117, 43, 123, 47, 129, 109, 135, 53, 141, 85, 147, 125, 153, 61, 159, 73, 165, 139, 171, 103, 177, 67, 183, 155, 189, 113, 195, 71, 201, 169, 207, 77, 213, 101, 219, 185, 225, 83

Offset: 1

Author

Antti Karttunen, Mar 01 2016

Keywords

• nonn

Comments

a(n) = the number located immediately below n in A255127 (square array generated by Ludic sieve) in the same column where n itself is, or in other words, the number removed in the next filtering stage at the same step as when n was removed in the A260738(n)-th stage.

Permutation of odd numbers.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..32999

Crossrefs

Cf. A255127, A260738, A260739.

Cf. A269171, A269356, A269358, A269382, A269385, A269387 (sequences that use this function).

Cf. A269380 (left inverse).

Cf. also A250469, A269369.

Programs

Scheme

(define (A269379 n) (if (= 1 n) n (A255127bi (+ (A260738 n) 1) (A260739 n)))) ;; Code for A255127bi given in A255127.

Formula

a(1) = 1; for n > 1, a(n) = A255127(A260738(n)+1, A260739(n)).

Other identities. For all n >= 1:

A269380(a(n)) = n.