cp's OEIS Frontend

A284559 a(n) = LCM of run lengths in binary representation of n.

%I A284559 #17 Oct 15 2022 14:09:00
%S A284559 1,1,1,2,2,1,2,3,3,2,1,2,2,2,3,4,4,3,2,2,2,1,2,3,6,2,2,2,6,3,4,5,5,4,
%T A284559 3,6,2,2,2,6,3,2,1,2,2,2,3,4,4,6,2,2,2,2,2,6,3,6,3,6,4,4,5,6,6,5,4,4,
%U A284559 6,3,6,3,6,2,2,2,2,2,6,4,4,3,2,2,2,1,2,3,6,2,2,2,6,3,4,5,10,4,6,6,2,2,2,6,6,2,2,2,2,2,6,4,12,3,6,6,6,3,6,3
%N A284559 a(n) = LCM of run lengths in binary representation of n.
%H A284559 Antti Karttunen, <a href="/A284559/b284559.txt">Table of n, a(n) for n = 0..10922</a>
%H A284559 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%H A284559 <a href="/index/Lc#lcm">Index entries for sequences related to lcm's</a>
%F A284559 a(n) = A167489(n) / A284558(n).
%e A284559 For n=12, A007088(12) = "1100" in binary, the run lengths are [2,2], thus a(12) = lcm(2,2) = 2.
%o A284559 (Scheme)
%o A284559 (define (A284559 n) (apply lcm (binexp->runcount1list n)))
%o A284559 ;; Or:
%o A284559 (define (A284559 n) (reduce lcm 1 (binexp->runcount1list n))) ;; For binexp->runcount1list, see the Program section of A227349.
%o A284559 (Python)
%o A284559 from math import lcm
%o A284559 from itertools import groupby
%o A284559 def a(n): return lcm(*(len(list(g)) for k, g in groupby(bin(n)[2:])))
%o A284559 print([a(n) for n in range(87)]) # _Michael S. Branicky_, Oct 15 2022
%Y A284559 Cf. A000975 (positions of ones).
%Y A284559 Cf. A007088, A167489, A227349, A284558, A284569, A284579.
%K A284559 nonn,base
%O A284559 0,4
%A A284559 _Antti Karttunen_, Apr 14 2017