A002457 as tables, graphs or sounds

A002457 formatted as a simple table:

`n`		`a(n)`
`0`		`1`
`1`		`6`
`2`		`30`
`3`		`140`
`4`		`630`
`5`		`2772`
`6`		`12012`
`7`		`51480`
`8`		`218790`
`9`		`923780`
`10`		`3879876`
`11`		`16224936`
`12`		`67603900`
`13`		`280816200`
`14`		`1163381400`
`15`		`4808643120`
`16`		`19835652870`
`17`		`81676217700`
`18`		`335780006100`
`19`		`1378465288200`
`20`		`5651707681620`
`21`		`23145088600920`
`22`		`94684453367400`

[1,6,30,140,630,2772,12012,51480,218790,923780, 3879876,16224936,67603900,280816200,1163381400, 4808643120,19835652870,81676217700,335780006100, 1378465288200,5651707681620,23145088600920, 94684453367400]

Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

AT&T Labs Research