A265859 Unluckiness of n.

0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2, 1, 3, 1, 0, 1, 2, 1, 0, 1, 4, 1, 2, 1, 0, 1, 0, 1, 2, 1, 0, 1, 3, 1, 2, 1, 0, 1, 5, 1, 2, 1, 0, 1, 0, 1, 2, 1, 6, 1, 4, 1, 2, 1, 3, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 2, 1, 0, 1, 3, 1, 2, 1, 7, 1, 0

Offset: 1

Author

Max Barrentine, Dec 17 2015

Keywords

• nonn

Comments

If n is lucky, a(n)=0; if n is unlucky, a(n) is the step at which n is rejected from the lucky number sieve.

Links

• Max Barrentine, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000959, A050505, A145649, A260437, A260438.

Cf. also arrays A255543, A255545.

Cf. A271420 (analogous sequence).

Programs

Scheme

(define (A265859 n) (* (- 1 (A145649 n)) (A260438 n))) ;; Antti Karttunen, Sep 11 2016

Formula

a(n) = (1-A145649(n)) * A260438(n). - Antti Karttunen, Sep 11 2016, corrected Nov 15 2019