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

Author

Antti Karttunen, Sep 11 2016

Keywords

• nonn

Examples

			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.
		

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10001
• Index entries for sequences generated by sieves

Crossrefs

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

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

Programs

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))))))