Coefficient of x^n in the expansion of ( (1-x+x^4) / (1-x) )^n.

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =4a(5) =5a(6) =6a(7) =7a(8) =36a(9) =81a(10) =145a(11) =231a(12) =562a(13) =1339a(14) =2835a(15) =5405a(16) =11316a(17) =25177a(18) =55149a(19) =114475a(20) =238869a(21) =513016a(22) =1114597a(23) =2382524a(24) =5052066a(25) =10786905a(26) =23242531a(27) =50010507a(28) =107127199a(29) =229474680