a(n) = (8*n + 18)*Pochhammer(n, 6) / 6!.

Terms

a(0) =0a(1) =26a(2) =238a(3) =1176a(4) =4200a(5) =12180a(6) =30492a(7) =68376a(8) =140712a(9) =270270a(10) =490490a(11) =848848a(12) =1410864a(13) =2264808a(14) =3527160a(15) =5348880a(16) =7922544a(17) =11490402a(18) =16353414a(19) =22881320a(20) =31523800a(21) =42822780a(22) =57425940a(23) =76101480a(24) =99754200a(25) =129442950a(26) =166399506a(27) =212048928a(28) =268031456a(29) =336226000