A101613 (2n)! * Sum[k=n..2n, 1/k].

3, 26, 684, 35664, 3068640, 392722560, 69878833920, 16484477184000, 4976250951168000, 1870345490614272000, 856314330237628416000, 469109144339151224832000, 302956190548293037916160000

Offset

1,1

Links

Table of n, a(n) for n=1..13.

Crossrefs

Cf. A101609, A101610, A101611, A101612, A000254, A046673, A052517.

Sequence in context: A129430 A005156 A355120 * A280222 A354652 A174811

Adjacent sequences: A101610 A101611 A101612 * A101614 A101615 A101616

Keyword

nonn,easy

Author

Ralf Stephan, Dec 10 2004

Status

approved