A079753 - OEIS

A079753

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'.

0, 3, 21, 136, 967, 7757, 69841, 698446, 7682951, 92195467, 1198541137, 16779575996, 251693640031, 4027098240601, 68460670090337, 1232292061626202, 23413549170897991, 468270983417959991, 9833690651777160001

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OFFSET

3,2

COMMENTS

The asymptotic value for large n is 0.19247...*n! = (e/2-7/6)*n!. See also comment for A079884.

REFERENCES

See under 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-1)*(n-2)/2 for n>=4 a(n) = A079752(n) + A079754(n)