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 A001811 M5185 N2253 #42 May 02 2022 08:31:38 %S A001811 1,25,450,7350,117600,1905120,31752000,548856000,9879408000, %T A001811 185513328000,3636061228800,74373979680000,1586644899840000, %U A001811 35272336619520000,816302647480320000,19645683716026368000,491142092900659200000,12740803704070041600000 %N A001811 Coefficients of Laguerre polynomials. %D A001811 M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 799. %D A001811 Cornelius Lanczos, Applied Analysis. Prentice-Hall, Englewood Cliffs, NJ, 1956, p. 519. %D A001811 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A001811 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A001811 T. D. Noe, <a href="/A001811/b001811.txt">Table of n, a(n) for n = 4..100</a> %H A001811 M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy]. %H A001811 Cornelius Lanczos, <a href="/A002457/a002457.pdf">Applied Analysis</a>. (Annotated scans of selected pages) %H A001811 <a href="/index/La#Laguerre">Index entries for sequences related to Laguerre polynomials</a>. %F A001811 a(n) = n!*n*(n-1)(n-2)(n-3)/(4!)^2. a(4)=1, a(n+1) = a(n) * (n+1)^2 / (n-3). %F A001811 a(n) = A021009(n, 4), n >= 4. %F A001811 E.g.f.: x^4/(4!*(1-x)^5). %F A001811 If we define f(n,i,x) = Sum_{k=i..n} Sum_{j=i..k} binomial(k,j) * Stirling1(n,k) * Stirling2(j,i) * x^(k-j) then a(n) = (-1)^n*f(n,4,-5), (n >= 4). - _Milan Janjic_, Mar 01 2009 %F A001811 From _Amiram Eldar_, May 02 2022: (Start) %F A001811 Sum_{n>=4} 1/a(n) = 64*(Ei(1) - gamma - e) + 272/3, where Ei(1) = A091725, gamma = A001620, and e = A001113. %F A001811 Sum_{n>=4} (-1)^n/a(n) = 544*(gamma - Ei(-1)) - 320/e - 944/3, where Ei(-1) = -A099285. (End) %e A001811 G.f. = x^4 + 25*x^5 + 450*x^6 + 7350*x^7 + 117600*x^8 + 1905120*x^9 + ... %p A001811 with(combstruct):ZL:=[st, {st=Prod(left, right), left=Set(U, card=r+2), right=Set(U, card<r), U=Sequence(Z, card>=1)}, labeled]: subs(r=2, stack): seq(count(subs(r=2, ZL), size=m), m=4..19) ; # _Zerinvary Lajos_, Feb 07 2008 %t A001811 Table[n! n (n - 1) (n - 2) (n - 3)/(4!)^2, {n, 4, 20}] (* _T. D. Noe_, Aug 10 2012 *) %o A001811 (Sage) [factorial(m) * binomial(m, 4) / 24 for m in range(4,19)] # _Zerinvary Lajos_, Jul 05 2008 %Y A001811 Cf. A053495. %Y A001811 Cf. A001113, A001620, A091725, A099285. %K A001811 nonn,easy %O A001811 4,2 %A A001811 _N. J. A. Sloane_ %E A001811 More terms from Larry Reeves (larryr(AT)acm.org), Feb 07 2001 %E A001811 Corrected by _T. D. Noe_, Aug 10 2012