A026030 as tables, graphs or sounds

A026030 formatted as a simple table:

`n`		`a(n)`
`2`		`1`
`3`		`4`
`4`		`15`
`5`		`56`
`6`		`209`
`7`		`780`
`8`		`2912`
`9`		`10880`
`10`		`40698`
`11`		`152456`
`12`		`572033`
`13`		`2150040`
`14`		`8095425`
`15`		`30535260`
`16`		`115377660`
`17`		`436698240`
`18`		`1655607390`
`19`		`6286707000`
`20`		`23908446510`
`21`		`91057063344`
`22`		`347281885818`
`23`		`1326262602104`
`24`		`5071418015120`
`25`		`19415851639296`
`26`		`74419447792340`

[1,4,15,56,209,780,2912,10880,40698,152456,572033, 2150040,8095425,30535260,115377660,436698240, 1655607390,6286707000,23908446510,91057063344, 347281885818,1326262602104,5071418015120, 19415851639296,74419447792340]

Last modified December 5 08:23 EST 2009. Contains 170348 sequences.

AT&T Labs Research