A117381 as tables, graphs or sounds

A117381 formatted as a simple table:

`n`		`a(n)`
`0`		`1`
`1`		`4`
`2`		`21`
`3`		`109`
`4`		`575`
`5`		`3047`
`6`		`16192`
`7`		`86171`
`8`		`458972`
`9`		`2445825`
`10`		`13037508`
`11`		`69509558`
`12`		`370634265`
`13`		`1976421031`
`14`		`10539858413`
`15`		`56208784808`
`16`		`299766435277`
`17`		`1598704176149`
`18`		`8526238418811`
`19`		`45472594256564`
`20`		`242517996824355`

[1,4,21,109,575,3047,16192,86171,458972,2445825, 13037508,69509558,370634265,1976421031, 10539858413,56208784808,299766435277, 1598704176149,8526238418811,45472594256564, 242517996824355]

Last modified December 16 17:18 EST 2009. Contains 170825 sequences.

AT&T Labs Research