a(n) = - a(n-1) - a(n-2) - a(n-3) + 50*(n-4) + 50*a(n-5) + 50*a(n-6) + 50*a(n-7), n >= 8.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =5a(6) =25a(7) =169a(8) =1a(9) =205a(10) =1225a(11) =8569a(12) =1a(13) =10205a(14) =61225a(15) =428569a(16) =1a(17) =510205a(18) =3061225a(19) =21428569a(20) =1a(21) =25510205a(22) =153061225a(23) =1071428569a(24) =1a(25) =1275510205a(26) =7653061225a(27) =53571428569a(28) =1a(29) =63775510205