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 A079751 #26 Jun 26 2022 09:43:04
%S A079751 0,1,6,37,260,2081,18730,187301,2060312,24723745,321408686,4499721605,
%T A079751 67495824076,1079933185217,18358864148690,330459554676421,
%U A079751 6278731538852000,125574630777040001,2637067246317840022,58015479418992480485,1334356026636827051156
%N A079751 Operation count to create all permutations of n distinct elements using the "streamlined" version of Algorithm L (lexicographic permutation generation) from Knuth's The Art of Computer Programming, Vol. 4, chapter 7.2.1.2. Sequence gives number of cases where the j search loop runs beyond j=n-3.
%C A079751 The asymptotic value for large n is 0.051615...*n! = (e - 8/3)*n!. See also comment for A079884.
%D A079751 See under A079884.
%H A079751 Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/lpgcount.txt">FORTRAN program for lexicographic permutation generation</a>.
%F A079751 a(3)=0, a(n) = n * a(n-1) + 1 for n >= 4.
%F A079751 For n >= 3, a(n) = floor(c*n!) where c = lim_{n->infinity} a(n)/n! = 0.05161516179237856869. - _Benoit Cloitre_
%F A079751 a(n) = Sum_{j=4..n} (n-j)! * binomial(n,j). - _Zerinvary Lajos_, Jul 31 2006
%F A079751 E.g.f.: (exp(x) - Sum_{k=0..3} x^k/k!) / (1 - x). - _Ilya Gutkovskiy_, Jun 26 2022
%p A079751 a:=n->sum((n-j)!*binomial(n,j),j=4..n): seq(a(n), n=3..25); # _Zerinvary Lajos_, Jul 31 2006
%t A079751 a[3] = 0; a[n_] := n*a[n - 1] + 1; Table[a[n], {n, 3, 21}]
%o A079751 FORTRAN program available at link
%Y A079751 Cf. A079885, A079750, A079752, A079753, A079754, A079755, A079756.
%K A079751 easy,nonn
%O A079751 3,3
%A A079751 _Hugo Pfoertner_, Jan 14 2003
%E A079751 Edited and extended by _Robert G. Wilson v_, Jan 22 2003