A116447 a(2n) = n, a(2n+1) = n!.

0, 1, 1, 1, 2, 2, 3, 6, 4, 24, 5, 120, 6, 720, 7, 5040, 8, 40320, 9, 362880, 10, 3628800, 11, 39916800, 12, 479001600, 13, 6227020800, 14, 87178291200, 15, 1307674368000, 16, 20922789888000, 17, 355687428096000, 18, 6402373705728000, 19, 121645100408832000

Offset: 0

Author

Parthasarathy Nambi, Mar 15 2006

Keywords

• nonn

Crossrefs

Cf. A051340.

Programs

Magma

&cat[[n, Factorial(n)]: n in [0..20]]; // Vincenzo Librandi, Mar 05 2015

Mathematica

Flatten[Table[{n, n!}, {n, 0, 20}]] (* Vincenzo Librandi, Mar 05 2015 *)
With[{nn=20},Riffle[Range[0,nn],Range[0,nn]!]] (* Harvey P. Dale, Jan 09 2016 *)

Extensions

More terms from Franklin T. Adams-Watters, Jun 02 2006