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

1,5

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

Formula

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

Prog

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

Crossrefs

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

Cf. also arrays A255543, A255545.

Cf. A271420 (analogous sequence).

Sequence in context: A257260 A334208 A159195 * A271420 A099313 A316491

Adjacent sequences: A265856 A265857 A265858 * A265860 A265861 A265862

Keyword

nonn

Author

Max Barrentine, Dec 17 2015

Status

approved