A000138 as tables, graphs or sounds

A000138 formatted as a simple table:

`n`		`a(n)`
`0`		`1`
`1`		`1`
`2`		`2`
`3`		`6`
`4`		`18`
`5`		`90`
`6`		`540`
`7`		`3780`
`8`		`31500`
`9`		`283500`
`10`		`2835000`
`11`		`31185000`
`12`		`372972600`
`13`		`4848643800`
`14`		`67881013200`
`15`		`1018215198000`
`16`		`16294848570000`
`17`		`277012425690000`
`18`		`4986223662420000`
`19`		`94738249585980000`
`20`		`1894745192712372000`

[1,1,2,6,18,90,540,3780,31500,283500,2835000, 31185000,372972600,4848643800,67881013200, 1018215198000,16294848570000,277012425690000, 4986223662420000,94738249585980000, 1894745192712372000]

Last modified December 15 00:47 EST 2009. Contains 170825 sequences.

AT&T Labs Research