A137974 as tables, graphs or sounds

A137974 formatted as a simple table:

`n`		`a(n)`
`0`		`1`
`1`		`1`
`2`		`6`
`3`		`45`
`4`		`410`
`5`		`4020`
`6`		`41826`
`7`		`452207`
`8`		`5033910`
`9`		`57300285`
`10`		`663912420`
`11`		`7804131660`
`12`		`92838682242`
`13`		`1115595461915`
`14`		`13521340799310`
`15`		`165104951405235`
`16`		`2029162664033790`
`17`		`25081468301798301`
`18`		`311593507408597920`

[1,1,6,45,410,4020,41826,452207,5033910,57300285, 663912420,7804131660,92838682242,1115595461915, 13521340799310,165104951405235,2029162664033790, 25081468301798301,311593507408597920]

Last modified December 6 13:45 EST 2009. Contains 170429 sequences.

AT&T Labs Research