%I #10 Jan 01 2024 13:28:26

%S 0,2,13,82,579,4638,41749,417498,4592487,55109854,716428113,

%T 10029993594,150449903923,2407198462782,40922373867309,

%U 736602729611578,13995451862619999,279909037252399998,5878089782300399977

%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 number of times the search for an element exchangeable with a_j has to be started.

%C The asymptotic value for large n is 0.11505...*n! = (17/6-e)*n!. See also comment for 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 - 2 for n>=4

%t a[3] = 0; a[n_] := n*a[n - 1] + n - 2; Table[a[n], {n, 3, 21}]

%o FORTRAN program available at link

%Y Cf. A079884, A079750, A079751, A079753, A079754, A079755, A079756.

%K easy,nonn

%O 3,2

%A _Hugo Pfoertner_, Jan 14 2003

%E Edited and extended by _Robert G. Wilson v_, Jan 22 2003