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 A086196 #14 Feb 16 2025 08:32:50
%S A086196 2,3,4,1,1,1,1,9,10,11,4,13,14,5,16,17,3,19,10,7,11,23,4,25,26,27,28,
%T A086196 29,10,31,32,33,34,35,36,37,19,39,20,41,3,43,22,45,23,47,24,7,10,17,
%U A086196 52,53,18,11,56,19,58,59,4,61,62,21,64,13,33,67,17,69,7,71,18,73,74
%N A086196 Incorrect version of A380267.
%C A086196 Previous name was: Denominators of running averages of A051904.
%C A086196 Due to a bug in the Mathematica code in the World of Mathematics page, the sequence was calculated with running averages over {A051904(1), 1, A051904(2), A051904(3), ... } with the first term removed. See A380267 for the correct sequence. - _Amiram Eldar_, Jan 18 2025
%H A086196 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/NivensConstant.html">Niven's Constant</a>.
%F A086196 a(n) = denominator((1 + Sum_{k=1..n} A051904(k))/(n+1)). - _Amiram Eldar_, Jan 18 2025
%e A086196 1/2, 2/3, 3/4, 1, 1, 1, 1, 11/9, 13/10, 14/11, ...
%t A086196 f[n_] := Min[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 A086196 Cf. A051904, A086195 (numerators), A380267.
%K A086196 nonn,easy,frac,dead
%O A086196 1,1
%A A086196 _Eric W. Weisstein_, Jul 11 2003