Second binomial transform of binomial(n+3, 3).

Terms

a(0) =1a(1) =6a(2) =30a(3) =136a(4) =579a(5) =2358a(6) =9288a(7) =35640a(8) =133893a(9) =494262a(10) =1797714a(11) =6456024a(12) =22930695a(13) =80660934a(14) =281309436a(15) =973599912a(16) =3346483977a(17) =11431295910a(18) =38828142342a(19) =131206405608a(20) =441271936971