A001998 as tables, graphs or sounds

A001998 formatted as a simple table:

`n`		`a(n)`
`0`		`1`
`1`		`2`
`2`		`4`
`3`		`10`
`4`		`25`
`5`		`70`
`6`		`196`
`7`		`574`
`8`		`1681`
`9`		`5002`
`10`		`14884`
`11`		`44530`
`12`		`133225`
`13`		`399310`
`14`		`1196836`
`15`		`3589414`
`16`		`10764961`
`17`		`32291602`
`18`		`96864964`
`19`		`290585050`
`20`		`871725625`
`21`		`2615147350`
`22`		`7845353476`
`23`		`23535971854`
`24`		`70607649841`
`25`		`211822683802`
`26`		`635467254244`
`27`		`1906400965570`

[1,2,4,10,25,70,196,574,1681,5002,14884,44530, 133225,399310,1196836,3589414,10764961,32291602, 96864964,290585050,871725625,2615147350, 7845353476,23535971854,70607649841,211822683802, 635467254244,1906400965570]

Last modified December 10 00:48 EST 2009. Contains 170565 sequences.

AT&T Labs Research