A276440 a(n) = greatest ludic number (A003309) that divides n.

1, 2, 3, 2, 5, 3, 7, 2, 3, 5, 11, 3, 13, 7, 5, 2, 17, 3, 1, 5, 7, 11, 23, 3, 25, 13, 3, 7, 29, 5, 1, 2, 11, 17, 7, 3, 37, 2, 13, 5, 41, 7, 43, 11, 5, 23, 47, 3, 7, 25, 17, 13, 53, 3, 11, 7, 3, 29, 1, 5, 61, 2, 7, 2, 13, 11, 67, 17, 23, 7, 71, 3, 1, 37, 25, 2, 77, 13, 1, 5, 3, 41, 83, 7, 17, 43, 29, 11, 89, 5, 91, 23, 3, 47

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..10001

Index entries for sequences generated by sieves

Example

a(19) = 1 as 19 is not a ludic number, but it is a prime, thus only ludic number that divides it is the very first one A003309(1) = 1.
a(589) = 1 also as 589 = 19*31 and both 19 and 31 are in A192505.

Prog

(Scheme)
(define (A276440 n) (let loop ((k 1) (mt 1)) (let ((t (A003309 k))) (cond ((> t n) mt) ((zero? (modulo n t)) (loop (+ 1 k) t)) (else (loop (+ 1 k) mt))))))

Crossrefs

Cf. A003309, A192505, A272565, A276568, A276569.

Differs from A006530 for the first time at n=19.

Sequence in context: A180506 A273283 A359612 * A162325 A324371 A197862

Adjacent sequences: A276437 A276438 A276439 * A276441 A276442 A276443

Keyword

nonn

Author

Antti Karttunen, Sep 11 2016

Status

approved