a(n) = A047848(5, n).

Terms

a(0) =1a(1) =2a(2) =10a(3) =74a(4) =586a(5) =4682a(6) =37450a(7) =299594a(8) =2396746a(9) =19173962a(10) =153391690a(11) =1227133514a(12) =9817068106a(13) =78536544842a(14) =628292358730