Coefficients for extrapolation.

Terms

a(0) =3a(1) =60a(2) =630a(3) =5040a(4) =34650a(5) =216216a(6) =1261260a(7) =7001280a(8) =37413090a(9) =193993800a(10) =981608628a(11) =4867480800a(12) =23728968900a(13) =114011377200a(14) =540972351000