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 A000442 #67 Jan 19 2023 11:09:53 %S A000442 1,1,8,216,13824,1728000,373248000,128024064000,65548320768000, %T A000442 47784725839872000,47784725839872000000,63601470092869632000000, %U A000442 109903340320478724096000000,241457638684091756838912000000,662559760549147780765974528000000,2236139191853373760085164032000000000 %N A000442 a(n) = (n!)^3. %C A000442 Permanent of upper right n X n corner of multiplication table (A003991). - _Marc LeBrun_, Dec 11 2003 %C A000442 a(n) is the number of set partitions of {1, 2, ..., 4n - 1, 4n} into blocks of size 4 in which the entries of each block mod 4 are distinct. For example, a(2) = 8 counts 1234-5678, 1678-2345, 1278-3456, 1346-2578, 1238-4567, 1467-2358, 1247-3568, 1368-2457. - _David Callan_, Mar 30 2007 %C A000442 a(n) is also the determinant of the symmetric n X n matrix M defined by M(i, j) = sigma_3(gcd(i, j)) for 1 <= i,j <= n, and n > 0, where sigma_3 is A001158. - _Enrique Pérez Herrero_, Aug 13 2011 %D A000442 F. Smarandache, "Properties of the Numbers", University of Craiova Archives, 1975; Arizona State University Special Collections, Tempe, AZ %H A000442 Vincenzo Librandi, <a href="/A000442/b000442.txt">Table of n, a(n) for n = 0..100</a> %H A000442 G. S. Kazandzidis, <a href="http://www.hms.gr/apothema/?s=sa&i=20">On a Conjecture of Moessner and a General Problem</a>, Bull. Soc. Math. Grèce, Nouvelle Série - vol. 2, fasc. 1-2, pp. 23-30, 1961. %H A000442 <a href="/index/Di#divseq">Index to divisibility sequences</a> %F A000442 a(n) = det(S(i+3, j), 1 <= i, j <= n), where S(n, k) are Stirling numbers of the second kind. - _Mircea Merca_, Apr 04 2013 %F A000442 From _Karol A. Penson_, Jul 28 2013: (Start) %F A000442 G.f. of hypergeometric type: sum(a(n)*z^n/(n!)^3, n = 0..infinity) = 1/(1-z); %F A000442 Integral representation as n-th moment of a positive function w(x) on a positive halfaxis (solution of the Stieltjes moment problem), in Maple notation: %F A000442 a(n) = int(x^n*w(x), x = 0..infinity), n >= 0, where w(x) = MeijerG([[], []], [[0, 0, 0]], []], x), w(0) = infinity, limit(w(x), x = infinity) = 0. %F A000442 w(x) is monotonically decreasing over (0, infinity). The Meijer G function above cannot be represented by any other known special function. This solution of the Stieltjes moment problem is not unique. %F A000442 Asymptotics: a(n) -> (1/16)*sqrt(2)*Pi^(3/2)*(32*n^2 + 8*n + 1)*(n)^(-1/2+3*n)*exp(-3*n), for n -> infinity. (End) %F A000442 D-finite with recurrence: a(n) -n^3*a(n-1)=0. - _R. J. Mathar_, Feb 16 2020 %F A000442 From _Amiram Eldar_, Nov 09 2020: (Start) %F A000442 a(n) = A000142(n)^3. %F A000442 Sum_{n>=0} 1/a(n) = A271574. (End) %F A000442 a(n) = [x^n] Product_{k=1..n} (1 + k^3*x). - _Vaclav Kotesovec_, Feb 19 2022 %p A000442 seq((n!)^3, n=0..14), # _Karol A. Penson_, Jul 28 2013 %t A000442 Table[(n!)^3, {n, 0, 20}] (* _Stefan Steinerberger_, Apr 14 2006 *) %o A000442 (PARI) a(n)=n!^3 \\ _Charles R Greathouse IV_, Jan 12 2012 %o A000442 (Magma) [Factorial(n)^3: n in [0..15]]; // _Vincenzo Librandi_, Jan 13 2012 %Y A000442 Cf. A000142, A003991, A271574. %Y A000442 Row n=3 of A225816. %K A000442 nonn,easy %O A000442 0,3 %A A000442 R. Muller