A167570 The third right hand column of triangle A167569.

6, 80, 1344, 27648, 675840, 19169280, 619315200, 22460497920, 903704739840, 39953262182400, 1925366729932800, 100453916344320000, 5641491941897011200, 339325293097805414400, 21763622246962692096000

Offset

3,1

Links

G. C. Greubel, Table of n, a(n) for n = 3..150

Formula

a(n) = 4^(n-3)*(n-3)!*(2*n-3)!/(2*n-5)!.

Mathematica

Table[4^(n-3) (n-3)! (2n-3)!/(2n-5)!, {n, 3, 20}] (* Harvey P. Dale, Nov 27 2011 *)

Crossrefs

Equals the third right hand column of triangle A167569.

Sequence in context: A229574 A240409 A275137 * A337564 A177776 A349528

Adjacent sequences: A167567 A167568 A167569 * A167571 A167572 A167573

Keyword

easy,nonn

Author

Johannes W. Meijer, Nov 10 2009

Status

approved