A221145 a(n) is the number of permutations of n elements with exactly one fixed point and no transpositions.
1, 0, 0, 8, 30, 144, 1120, 9120, 80892, 808640, 8908416, 106889760, 1389405160, 19452003648, 291782125440, 4668506495744, 79364583206160, 1428562661736960, 27142690917071872, 542853814698737280, 11399930105272855776, 250798462399704792320
Offset: 1
Keywords
Examples
For n = 4 the a(4) = 8 solutions are (123), (124), (132), (134), (142), (143), (234), (243)
Formula
Equals n*A038205(n-1). - Giovanni Resta, Nov 13 2012
Extensions
Edited by N. J. A. Sloane, Jan 03 2013