Complement of A340745.

Terms

a(0) =1a(1) =4a(2) =11a(3) =30a(4) =79a(5) =210a(6) =566a(7) =1530a(8) =4150a(9) =11269a(10) =30620a(11) =83220a(12) =226199a(13) =614855a(14) =1671330a(15) =4543124a(16) =12349468a(17) =33569309a(18) =91250817a(19) =248045411a(20) =674257302a(21) =1832821341a(22) =4982124913a(23) =13542819584a(24) =36813200344a(25) =100068653503a(26) =272014802375a(27) =739412894325