a(n) = binomial coefficient C(n,24).

Terms

a(0) =1a(1) =25a(2) =325a(3) =2925a(4) =20475a(5) =118755a(6) =593775a(7) =2629575a(8) =10518300a(9) =38567100a(10) =131128140a(11) =417225900a(12) =1251677700a(13) =3562467300a(14) =9669554100a(15) =25140840660a(16) =62852101650a(17) =151584480450a(18) =353697121050a(19) =800472431850