a(n) = (1/4)*(7*n + 17)*(5*n + 6)*Pochhammer(n, 6) / 6!.

Terms

a(0) =0a(1) =66a(2) =868a(3) =5586a(4) =24570a(5) =84630a(6) =245322a(7) =625086a(8) =1440582a(9) =3063060a(10) =6096090a(11) =11479468a(12) =20624604a(13) =35587188a(14) =59283420a(15) =95756580a(16) =150501204a(17) =230852622a(18) =346450104a(19) =509782350a(20) =736824550a(21) =1047776730a(22) =1467913590a(23) =2028556530a(24) =2768179050a(25) =3733657200a(26) =4981677246a(27) =6580313208