Shifts 2 places left under inverse binomial transform.

Terms

a(0) =1a(1) =2a(2) =1a(3) =1a(4) =-2a(5) =3a(6) =-7a(7) =22a(8) =-71a(9) =231a(10) =-794a(11) =2945a(12) =-11679a(13) =48770a(14) =-212823a(15) =969221a(16) =-4605674a(17) =22802431a(18) =-117322423a(19) =625743878a(20) =-3452893503a(21) =19684083947a(22) =-115787084242a(23) =701935339725