Second binomial transform of C(n+2,2).

Terms

a(0) =1a(1) =5a(2) =22a(3) =90a(4) =351a(5) =1323a(6) =4860a(7) =17496a(8) =61965a(9) =216513a(10) =747954a(11) =2558790a(12) =8680203a(13) =29229255a(14) =97785144a(15) =325241892a(16) =1076168025a(17) =3544180029a(18) =11622614670a(19) =37967207922a(20) =123587135991a(21) =400980206115