a(n) = 14*(n+1)*binomial(n+5,8).

Terms

a(0) =56a(1) =630a(2) =3780a(3) =16170a(4) =55440a(5) =162162a(6) =420420a(7) =990990a(8) =2162160a(9) =4424420a(10) =8576568a(11) =15872220a(12) =28217280a(13) =48430620a(14) =80582040a(15) =130423524a(16) =205931880a(17) =317983050a(18) =481180700a(19) =714864150a(20) =1044323280a(21) =1502250750a(22) =2130464700a(23) =2981938050a(24) =4123173600a(25) =5636967336a(26) =7625605680