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 A291511 #4 Aug 25 2017 23:40:46
%S A291511 -23,-24,-23,-24,-23,-24,-23,-24,-27,-30,-33,-36,-39,-42,-45,-48,-51,
%T A291511 -54,-57,-60,-63,-66,-69,-72,-75,-78,-81,-84,-87,-90,-93,-96,-99,-102,
%U A291511 -105,-108,-111,-114,-117,-120,-123,-126,-129,-132,-135,-138,-141,-144,-147,-150,-153,-156,-159,-162,-165,-168,-171,-174,-177,-180,-183,-186,-189,-192,-195,-198,-201,-204,-207,-210
%N A291511 The arithmetic function uhat(n,2,6).
%H A291511 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 1.6.4.
%t A291511 delta[r_, k_, d_] := If[r < k, (k - r)*r - (d - 1), If[k < r && r < d, (d - r)*(r - k) - (d - 1), If[k == r && r == d, d - 1, 0]]] uhat[n_, m_, h_] := (dx = Divisors[n]; dmin = n; For[i = 1, i ≤ Length[dx], i++, d = dx[[i]]; k = m - d*Ceiling[m/d] + d; r = h - d*Ceiling[h/d] + d; If[h ≤ Min[k, d - 1], dmin = Min[dmin, n, (h*Ceiling[m/d] - h + 1)*d, h*m - h*h + 1], dmin = Min[dmin, n, h*m - h*h + 1 - delta[r, k, d]]]]; dmin) Table[uhat[n, 2, 6], {n, 1, 70}]
%Y A291511 Cf. A289435, A289436, A289437, A289438, A289439, A289440, A289441.
%K A291511 sign
%O A291511 1,1
%A A291511 _Robert Price_, Aug 25 2017