A260437 Column index to A255543: if n is Lucky number then a(n) = 0, otherwise a(n) = the position at the stage where n is removed in the Lucky sieve.

0, 1, 0, 2, 1, 3, 0, 4, 0, 5, 2, 6, 0, 7, 0, 8, 3, 9, 1, 10, 0, 11, 4, 12, 0, 13, 1, 14, 5, 15, 0, 16, 0, 17, 6, 18, 0, 19, 2, 20, 7, 21, 0, 22, 1, 23, 8, 24, 0, 25, 0, 26, 9, 27, 1, 28, 2, 29, 10, 30, 3, 31, 0, 32, 11, 33, 0, 34, 0, 35, 12, 36, 0, 37, 0, 38, 13, 39, 0, 40, 4, 41, 14, 42, 1, 43, 0, 44, 15, 45, 3, 46, 0, 47, 16, 48, 2, 49, 0, 50, 17, 51, 5, 52

Offset

1,4

Links

Antti Karttunen, Table of n, a(n) for n = 1..10003

Formula

Other identities. For all n >= 1:

a(n) = A260429(n) - 1.

Iff A145649(n) = 1, then a(n) = 0.

a(2n) = n.

a(A219178(n)) = 1.

A255543(A260438(A050505(n)), a(A050505(n))) = A050505(n).

Prog

(Scheme) (define (A260437 n) (cond ((not (zero? (A145649 n))) 0) ((even? n) (/ n 2)) (else (let searchrow ((row 2)) (let searchcol ((col 1)) (cond ((>= (A255543bi row col) n) (if (= (A255543bi row col) n) col (searchrow (+ 1 row)))) (else (searchcol (+ 1 col))))))))) ;; Code for A255543bi given in A255543.

Crossrefs

One less than A260429.

Cf. A000959, A050505, A145649, A219178, A255543.

Cf. also A260438 (corresponding row index).

Sequence in context: A197386 A357991 A096269 * A262677 A307742 A297109

Adjacent sequences: A260434 A260435 A260436 * A260438 A260439 A260440

Keyword

nonn

Author

Antti Karttunen, Aug 02 2015

Status

approved