A208147 Sequence generated from A089080.

1, 2, 6, 12, 48, 96, 288, 576, 2880, 5760, 17280, 34560, 138240, 276480, 829440, 1658880, 9953280, 19906560, 59719680, 119439360, 477757440, 955514880, 2866544640, 5733089280, 28665446400, 57330892800, 171992678400, 343985356800, 1375941427200, 2751882854400

Offset: 1

Author

Gary W. Adamson, Feb 23 2012

Keywords

• nonn
• easy

Examples

			a(5) = 48 = A089080(5) * a(4) = 4 * 12.
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..2268

Crossrefs

Cf. A000142, A067281, A089080, A001511.

Programs

Maple

seq(mul(padic[ordp](2*k,2), k=1..2*n-2), n=1..40); # Ridouane Oudra, Nov 24 2024

Formula

a(1) = 1; for n>1, a(n) = A089080(n) * a(n-1).

a(n) = (2*n-1)!/A067281(2*n-1). - Alois P. Heinz, Dec 11 2023

a(n) = Product_{k=1..2*n-2} A001511(k). - Ridouane Oudra, Nov 24 2024