A079752 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.

0, 2, 13, 82, 579, 4638, 41749, 417498, 4592487, 55109854, 716428113, 10029993594, 150449903923, 2407198462782, 40922373867309, 736602729611578, 13995451862619999, 279909037252399998, 5878089782300399977

Offset

3,2

Comments

The asymptotic value for large n is 0.11505...*n! = (17/6-e)*n!. See also comment for A079884

Links

Table of n, a(n) for n=3..21.

Hugo Pfoertner, FORTRAN program for lexicographic permutation generation.

Formula

a(3)=0, a(n) = n * a(n-1) + n - 2 for n>=4

Mathematica

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

Prog

FORTRAN program available at link

Crossrefs

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

Sequence in context: A020059 A162772 A317892 * A156018 A285795 A134148

Adjacent sequences: A079749 A079750 A079751 * A079753 A079754 A079755

Keyword

easy,nonn

Author

Hugo Pfoertner, Jan 14 2003

Extensions

Edited and extended by Robert G. Wilson v, Jan 22 2003

Status

approved