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 A268592 #15 Oct 17 2018 08:55:45
%S A268592 12,3,4,6,12,25,60,150,400,1107,3180,9386,28404,87711,275764,880470,
%T A268592 2849916,9336508,30918732,103384758,348725540,1185630123,4060210764,
%U A268592 13996354586,48541672872,169293988125,593488622344,2090567755278,7396924802052,26281018091013,93738717046476,335563502259798
%N A268592 a(n) = (6/n^3) * Sum_{d|n} moebius(n/d)*binomial(2*d,d).
%H A268592 G. C. Greubel, <a href="/A268592/b268592.txt">Table of n, a(n) for n = 1..1500</a>
%H A268592 R. R. Aidagulov, M. A. Alekseyev. On p-adic approximation of sums of binomial coefficients. Journal of Mathematical Sciences 233:5 (2018), 626-634. doi:<a href="http://doi.org/10.1007/s10958-018-3948-0">10.1007/s10958-018-3948-0</a> arXiv:<a href="http://arxiv.org/abs/1602.02632">1602.02632</a>
%F A268592 a(n) = A007727(n)*6/n^3 = A045630(n)*12/n^3 = A060165(n)*6/n^2 = A022553(n)*12/n^2 = A268619(n)*6/n.
%F A268592 For n == 0, 1, or 3 (mod 4), a(n) = 2*A254593(n); for n == 2 (mod 4), a(n) = 2*A254593(n) - A254593(n/2)/2.
%t A268592 a[n_] := (6/n^3)* DivisorSum[n, MoebiusMu[n/#] Binomial[2 #, #] &]; Array[a, 50] (* _G. C. Greubel_, Dec 15 2017 *)
%o A268592 (PARI) { a(n) = sumdiv(n, d, moebius(n/d)*binomial(2*d, d))*6/n^3; }
%Y A268592 Cf. A254593, A268618, A268619.
%K A268592 nonn
%O A268592 1,1
%A A268592 _Max Alekseyev_, Feb 07 2016