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 A346411 #5 Jul 15 2021 21:21:26 %S A346411 0,1,-3,4,-8,1,353,27224,1871840,147012849,13684928021,1514370713340, %T A346411 197964773810648,30300949591876913,5380510834911767033, %U A346411 1098630080602791984784,255851291397441057781120,67450889282916741495608737,19994198644782014829579657837,6623096362909598587714211804212 %N A346411 a(n) = (n!)^2 * Sum_{k=0..n-1} (-1)^k / ((n-k) * k!)^2. %F A346411 Sum_{n>=0} a(n) * x^n / (n!)^2 = polylog(2,x) * BesselJ(0,2*sqrt(x)). %t A346411 Table[(n!)^2 Sum[(-1)^k/((n - k) k!)^2, {k, 0, n - 1}], {n, 0, 19}] %t A346411 nmax = 19; CoefficientList[Series[PolyLog[2, x] BesselJ[0, 2 Sqrt[x]], {x, 0, nmax}], x] Range[0, nmax]!^2 %Y A346411 Cf. A002741, A073701, A336292, A340789, A346410. %K A346411 sign %O A346411 0,3 %A A346411 _Ilya Gutkovskiy_, Jul 15 2021