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 A290981 #8 Aug 21 2017 13:00:30
%S A290981 0,1,0,1,2,1,1,3,2,2,4,2,2,5,2,3,6,3,4,7,4,4,8,5,4,9,4,5,10,5,5,11,6,
%T A290981 7,12,6,6,13,8,7,14,7,8,15,8,8,16,8,10,17,8,9,18,11,9,19,10,10,20,10,
%U A290981 10,21,10,13,22,11,12,23,14
%N A290981 The arithmetic function v_4(n,6).
%D A290981 J. Butterworth, Examining the arithmetic function v_g(n,h). Research Papers in Mathematics, B. Bajnok, ed., Gettysburg College, Vol. 8 (2008).
%H A290981 Bela Bajnok, <a href="https://arxiv.org/abs/1705.07444">Additive Combinatorics: A Menu of Research Problems</a>, arXiv:1705.07444 [math.NT], May 2017. See Table in Section 1.6.1.
%t A290981 v[g_, n_, h_] := (d = Divisors[n]; Max[(Floor[(d - 1 - GCD[d, g])/h] + 1)*n/d]); Table[v[4, n, 6], {n, 2, 70}]
%t A290981 a[n_]:=n Max[Table[(Floor[(d - 1 - GCD[d, 4])/6] + 1)/d, {d, Divisors[n]}]]; Table[a[n], {n, 2, 100}] (* _Vincenzo Librandi_, Aug 19 2017 *)
%Y A290981 Cf. A289435, A289436, A289437, A289438, A289439, A289440, A289441.
%K A290981 nonn
%O A290981 2,5
%A A290981 _Robert Price_, Aug 16 2017