A018211 as tables, graphs or sounds

A018211 formatted as a simple table:

`n`		`a(n)`
`0`		`1`
`1`		`4`
`2`		`20`
`3`		`60`
`4`		`170`
`5`		`396`
`6`		`868`
`7`		`1716`
`8`		`3235`
`9`		`5720`
`10`		`9752`
`11`		`15912`
`12`		`25236`
`13`		`38760`
`14`		`58200`
`15`		`85272`
`16`		`122661`
`17`		`173052`
`18`		`240460`
`19`		`328900`
`20`		`444158`
`21`		`592020`
`22`		`780572`
`23`		`1017900`
`24`		`1315015`
`25`		`1682928`
`26`		`2136304`
`27`		`2689808`
`28`		`3362600`
`29`		`4173840`
`30`		`5148144`
`31`		`6310128`

[1,4,20,60,170,396,868,1716,3235,5720,9752,15912, 25236,38760,58200,85272,122661,173052,240460, 328900,444158,592020,780572,1017900,1315015, 1682928,2136304,2689808,3362600,4173840,5148144, 6310128]

Last modified December 1 19:22 EST 2009. Contains 167811 sequences.

AT&T Labs Research