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 A290978 #10 Aug 21 2017 22:13:41
%S A290978 0,1,1,1,2,2,2,3,2,2,4,3,4,5,4,4,6,4,5,7,4,5,8,5,6,9,8,6,10,6,8,11,8,
%T A290978 10,12,8,8,13,10,8,14,9,11,15,10,10,16,14,10,17,13,11,18,11,16,19,12,
%U A290978 12,20,12,12,21,16,15,22,14,17,23,20
%N A290978 The arithmetic function v_2(n,5).
%D A290978 J. Butterworth, Examining the arithmetic function v_g(n,h). Research Papers in Mathematics, B. Bajnok, ed., Gettysburg College, Vol. 8 (2008).
%H A290978 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 A290978 v[g_, n_, h_] := (d = Divisors[n]; Max[(Floor[(d - 1 - GCD[d, g])/h] + 1)*n/d]); Table[v[2, n, 5], {n, 2, 70}]
%t A290978 a[n_]:=n Max[Table[(Floor[(d - 1 - GCD[d, 2])/5] + 1)/d, {d, Divisors[n]}]]; Table[a[n], {n, 2, 100}] (* _Vincenzo Librandi_, Aug 17 2017 *)
%Y A290978 Cf. A289435, A289436, A289437, A289438, A289439, A289440, A289441.
%K A290978 nonn
%O A290978 2,5
%A A290978 _Robert Price_, Aug 16 2017