%I #6 Jan 17 2015 11:36:31
%S 1,2,6,26,130,785,5497,43983,395847,3958473,43543211,522518536,
%T 6792740972,95098373611,1426475604177,22823609666834,388001364336187,
%U 6984024558051373,132696466602976097,2653929332059521943
%N [ exp(2/23)*n! ].
%t With[{c=Exp[2/23]},Floor[c*Range[20]!]] (* _Harvey P. Dale_, Jan 17 2015 *)
%K nonn
%O 1,2
%A _Simon Plouffe_