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%I #14 Jan 11 2013 15:25:21
%S 0,3,21,136,967,7757,69841,698446,7682951,92195467,1198541137,
%T 16779575996,251693640031,4027098240601,68460670090337,
%U 1232292061626202,23413549170897991,468270983417959991,9833690651777160001
%N 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 total executions of step L3.1'.
%C The asymptotic value for large n is 0.19247...*n! = (e/2-7/6)*n!. See also comment for A079884.
%D See under A079884
%H Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/lpgcount.txt">FORTRAN program for lexicographic permutation generation</a>
%F a(3)=0, a(n)= n*a(n-1) + (n-1)*(n-2)/2 for n>=4 a(n) = A079752(n) + A079754(n)
%F For n>=3, a(n)=floor(c*n!-(n-1)/2) where c=limit n-->infinity a(n)/n!= 0.192474247562855951... - _Benoit Cloitre_, Jan 20 2003
%t a[3] = 0; a[n_] := n*a[n - 1] + (n - 1)*(n - 2)/2; Table[a[n], {n, 3, 21}]
%o FORTRAN program available at link
%Y Cf. A079884, A079750, A079751, A079752, A079754, A079755, A079756.
%K nonn
%O 3,2
%A _Hugo Pfoertner_, Jan 16 2003
%E Edited and extended by _Robert G. Wilson v_, Jan 22 2003
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