A025225 as tables, graphs or sounds

A025225 formatted as a simple table:

`n`		`a(n)`
`1`		`2`
`2`		`4`
`3`		`16`
`4`		`80`
`5`		`448`
`6`		`2688`
`7`		`16896`
`8`		`109824`
`9`		`732160`
`10`		`4978688`
`11`		`34398208`
`12`		`240787456`
`13`		`1704034304`
`14`		`12171673600`
`15`		`87636049920`
`16`		`635361361920`
`17`		`4634400522240`
`18`		`33985603829760`
`19`		`250420238745600`
`20`		`1853109766717440`

[2,4,16,80,448,2688,16896,109824,732160,4978688, 34398208,240787456,1704034304,12171673600, 87636049920,635361361920,4634400522240, 33985603829760,250420238745600,1853109766717440]

Last modified December 9 18:50 EST 2009. Contains 170568 sequences.

AT&T Labs Research