A269370 - OEIS

A269370

a(1) = 1, after which, for odd n: a(n) = A260439(n)-th number k for which A260438(k) = A260438(n)-1, and for even n: a(n) = a(n/2).

1, 1, 2, 1, 4, 2, 3, 1, 7, 4, 6, 2, 9, 3, 13, 1, 8, 7, 5, 4, 15, 6, 10, 2, 21, 9, 19, 3, 12, 13, 25, 1, 31, 8, 14, 7, 33, 5, 11, 4, 16, 15, 37, 6, 27, 10, 18, 2, 43, 21, 49, 9, 20, 19, 45, 3, 39, 12, 22, 13, 17, 25, 51, 1, 24, 31, 63, 8, 67, 14, 26, 7, 69, 33, 73, 5, 28, 11, 75, 4, 23, 16, 30, 15, 55, 37, 79, 6, 32, 27, 61, 10, 87, 18, 34, 2

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OFFSET

1,3

COMMENTS

For odd numbers n > 1, a(n) tells which term is on the immediately preceding row of A255551 (square array generated by Lucky sieve), in the same column where n itself is.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..11017

FORMULA

a(1) = 1; after which for even n, a(n) = a(n/2), and for odd n, a(n) = A255551(A260438(n)-1, A260439(n)).

Other identities. For all n >= 1:

a(A269369(n)) = n.

PROG

(Scheme) (define (A269370 n) (cond ((= 1 n) n) ((even? n) (A269370 (/ n 2))) (else (A255551bi (- (A260438 n) 1) (A260439 n))))) ;; Code for A255551bi given in A255551.

CROSSREFS

Cf. A255551, A260438, A260439, A269369.

Cf. also A268674, A269380.

Sequence in context: A305422 A007733 A128520 * A123755 A118291 A118290

Adjacent sequences: A269367 A269368 A269369 * A269371 A269372 A269373

KEYWORD

nonn

AUTHOR

Antti Karttunen, Mar 01 2016

STATUS

approved