A057087 as tables, graphs or sounds

A057087 formatted as a simple table:

`n`		`a(n)`
`0`		`1`
`1`		`4`
`2`		`20`
`3`		`96`
`4`		`464`
`5`		`2240`
`6`		`10816`
`7`		`52224`
`8`		`252160`
`9`		`1217536`
`10`		`5878784`
`11`		`28385280`
`12`		`137056256`
`13`		`661766144`
`14`		`3195289600`
`15`		`15428222976`
`16`		`74494050304`
`17`		`359689093120`
`18`		`1736732573696`
`19`		`8385686667264`
`20`		`40489676963840`
`21`		`195501454524416`

[1,4,20,96,464,2240,10816,52224,252160,1217536, 5878784,28385280,137056256,661766144,3195289600, 15428222976,74494050304,359689093120, 1736732573696,8385686667264,40489676963840, 195501454524416]

Last modified December 1 19:22 EST 2009. Contains 167811 sequences.

AT&T Labs Research