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 A285337 #16 Jun 27 2025 10:53:17 %S A285337 1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,3,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1, %T A285337 1,3,1,1,1,4,1,1,1,1,3,1,1,8,1,5,1,1,1,3,1,4,1,1,1,2,1,1,3,1,1,1,1,1, %U A285337 1,1,1,3,1,1,5,1,1,1,1,4,1,1,1,2,1,1,1,1,1,3,1,1,1,1,1,8,1,7,1,5,1,1,1,1,1,1,1,3,1,1,1,4,1,1,1,1,1,1,1,4 %N A285337 a(n) = denominator of A065642(n)/n. %H A285337 Antti Karttunen, <a href="/A285337/b285337.txt">Table of n, a(n) for n = 1..10000</a> %o A285337 (Scheme) (define (A285337 n) (denominator (/ (A065642 n) n))) %o A285337 (Python) %o A285337 from sympy import primefactors, prod, Integer %o A285337 def a007947(n): return 1 if n<2 else prod(primefactors(n)) %o A285337 def a065642(n): %o A285337 if n==1: return 1 %o A285337 r=a007947(n) %o A285337 n += r %o A285337 while a007947(n)!=r: %o A285337 n+=r %o A285337 return n %o A285337 def a(n): return (a065642(n)/Integer(n)).denominator # _Indranil Ghosh_, Apr 20 2017 %Y A285337 Cf. A065642, A285100 (positions of ones), A284342 (positions of terms > 1). %Y A285337 Cf. A285336 for the numerator. %K A285337 nonn,frac %O A285337 1,12 %A A285337 _Antti Karttunen_, Apr 19 2017