A053505 as tables, graphs or sounds

A053505 formatted as a simple table:

`n`		`a(n)`
`0`		`1`
`1`		`1`
`2`		`2`
`3`		`6`
`4`		`18`
`5`		`90`
`6`		`540`
`7`		`3060`
`8`		`20700`
`9`		`145980`
`10`		`1459800`
`11`		`13854600`
`12`		`140059800`
`13`		`1514748600`
`14`		`15869034000`
`15`		`285268878000`
`16`		`4109761962000`
`17`		`59488383690000`
`18`		`935767530036000`
`19`		`13364309726748000`
`20`		`240338216104020000`
`21`		`4540941256642020000`

[1,1,2,6,18,90,540,3060,20700,145980,1459800, 13854600,140059800,1514748600,15869034000, 285268878000,4109761962000,59488383690000, 935767530036000,13364309726748000, 240338216104020000,4540941256642020000]

Last modified November 30 13:13 EST 2009. Contains 167758 sequences.

AT&T Labs Research