This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A280694 #12 Jan 12 2017 07:18:45 %S A280694 1,2,3,4,1,3,7,4,3,2,11,4,1,7,3,4,1,18,1,4,7,11,1,4,1,2,3,7,29,3,1,4, %T A280694 11,2,7,18,1,2,3,4,1,7,1,11,3,2,47,4,7,2,3,4,1,18,11,7,3,29,1,4,1,2,7, %U A280694 4,1,11,1,4,3,7,1,18,1,2,3,76,11,3,1,4,3,2,1,7,1,2,29,11,1,18,7,4,3,47,1,4,1,7,11,4,1,3,1,4,7,2,1,18,1,11,3,7,1 %N A280694 Largest Lucas number (A000032) dividing n. %H A280694 Antti Karttunen, <a href="/A280694/b280694.txt">Table of n, a(n) for n = 1..15127</a> %F A280694 a(n) = n / A280695(n). %F A280694 Other identities. For all n >= 1: %F A280694 a(A000032(n)) = A000032(n). %F A280694 a(A057854(n)) = A280696(A057854(n)). %F A280694 a(A000045(n)) = A280699(n). %o A280694 (Scheme) %o A280694 ;; A stand-alone program: %o A280694 (define (A280694 n) (let loop ((l1 1) (l2 3) (lpd 1)) (cond ((> l1 n) (if (and (= 1 lpd) (even? n)) 2 lpd)) ((zero? (modulo n l1)) (loop l2 (+ l1 l2) l1)) (else (loop l2 (+ l1 l2) lpd))))) %Y A280694 Cf. A000032, A054494, A280695, A280699. %Y A280694 Cf. A057854 (gives the positions n > 1 where this sequence and A280696 obtain equal values). %K A280694 nonn %O A280694 1,2 %A A280694 _Antti Karttunen_, Jan 11 2017