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 A291268 #11 Feb 20 2025 06:30:45
%S A291268 1,0,2,2,3,3,4,3,5,5,6,6,7,6,8,8,9,9,10,9,11,11,12,12,13,12,14,14,15,
%T A291268 15,16,15,17,17,18,18,19,18,20,20,21,21,22,21,23,23,24,24,25,24,26,26,
%U A291268 27,27,28,27,29,29,30,30,31,30,32,32,33,33,34,33,35
%N A291268 The arithmetic function v_3(n,2).
%D A291268 J. Butterworth, Examining the arithmetic function v_g(n,h). Research Papers in Mathematics, B. Bajnok, ed., Gettysburg College, Vol. 8 (2008).
%H A291268 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.
%F A291268 a(n) = (n + gcd(n,6) - 2*gcd(n,3))/2. - _Ridouane Oudra_, Feb 17 2025
%F A291268 Sum_{n>=4} (-1)^(n+1)/a(n) = 1 - Pi/(6*sqrt(3)) - log(3)/2. - _Amiram Eldar_, Feb 20 2025
%t A291268 v[g_, n_, h_] := (d = Divisors[n]; Max[(Floor[(d - 1 - GCD[d, g])/h] + 1)*n/d]); Table[v[3, n, 2], {n, 2, 70}]
%Y A291268 Cf. A289435, A289436, A289437, A289438, A289439, A289440, A289441.
%K A291268 nonn
%O A291268 2,3
%A A291268 _Robert Price_, Aug 21 2017