A092978 (Product of first n even numbers)/(product of first k odd numbers) where k is chosen to give the least integer.

2, 8, 16, 128, 256, 3072, 6144, 98304, 196608, 3932160, 7864320, 188743680, 25165824, 704643072, 21139292160, 676457349120, 1352914698240, 48704929136640, 4638564679680, 185542587187200, 7792788661862400

Offset

1,1

Links

Table of n, a(n) for n=1..21.

Formula

For n even, a(n+1)=2*a(n); for n odd, a(n+1)=2(n+1)*a(n). For n even, a(n)=[2^(3n/2)]*(n/2)!; for n odd, a(n)=[2^( (3n-1)/2)]*((n-1)/2)!. - Mark Hudson (mrmarkhudson(AT)hotmail.com), Jul 23 2004

Example

a(5) = 256 = (2*4*6*8*10)/(1*3*5) as (2*4*6*8*10)/(1*3*5*7) is not an integer, here k = 3.

Crossrefs

Sequence in context: A353820 A199043 A046161 * A280777 A013516 A259688

Adjacent sequences: A092975 A092976 A092977 * A092979 A092980 A092981

Keyword

nonn

Author

Amarnath Murthy, Mar 27 2004

Extensions

More terms from Mark Hudson (mrmarkhudson(AT)hotmail.com), Jul 23 2004

Corrected and extended by Sam Handler (sam_5_5_5_0(AT)yahoo.com), Oct 23 2004

Status

approved