Shifts 4 places left under binomial transform.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =0a(5) =0a(6) =0a(7) =1a(8) =4a(9) =10a(10) =20a(11) =36a(12) =68a(13) =166a(14) =540a(15) =1961a(16) =7012a(17) =23878a(18) =78004a(19) =250311a(20) =815196a(21) =2787806a(22) =10232556a(23) =40266382a(24) =166608080a(25) =708407020a(26) =3046352440a(27) =13161936881a(28) =57188405288a(29) =251328286460