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 A086198 #13 Feb 16 2025 08:32:50
%S A086198 2,3,4,1,1,1,1,9,10,11,4,13,7,15,4,17,18,19,5,7,22,23,8,25,13,9,2,29,
%T A086198 2,31,32,33,34,35,36,37,19,39,2,41,21,43,2,45,23,47,2,49,25,51,52,53,
%U A086198 9,55,7,57,29,59,30,61,62,9,16,65,66,67,68,23,5,71,12,73,37,75,76,77
%N A086198 Incorrect version of A380265.
%C A086198 Previous name was: Denominators of running averages of A051903.
%C A086198 Due to a bug in the Mathematica code in the World of Mathematics page, the sequence was calculated with running averages over {A051903(1), 1, A051903(2), A051903(3), ... } with the first term removed. See A380265 for the correct sequence. - _Amiram Eldar_, Jan 18 2025
%H A086198 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/NivensConstant.html">Niven's Constant</a>.
%F A086198 a(n) = denominator((1 + Sum_{k=1..n} A051903(k))/(n+1)). - _Amiram Eldar_, Jan 18 2025
%e A086198 1/2, 2/3, 3/4, 1, 1, 1, 1, 11/9, 13/10, 14/11, ...
%t A086198 f[n_] := Max[FactorInteger[n][[;; , 2]]]; f[1] = 0; With[{m = 100}, Denominator[(1 + Accumulate[Array[f, m]]) / Range[2, m+1]]] (* _Amiram Eldar_, Jan 18 2025 *)
%Y A086198 Cf. A051903, A086197 (numerators), A380265.
%K A086198 nonn,easy,frac,dead
%O A086198 1,1
%A A086198 _Eric W. Weisstein_, Jul 11 2003