Number of compositions of 2n into n squarefree parts.

Terms

a(0) =1a(1) =1a(2) =3a(3) =7a(4) =23a(5) =76a(6) =267a(7) =932a(8) =3263a(9) =11410a(10) =40028a(11) =140955a(12) =498467a(13) =1769249a(14) =6299282a(15) =22485487a(16) =80435919a(17) =288275461a(18) =1034862558a(19) =3720499175a(20) =13393720428a(21) =48275699654a(22) =174194970601a(23) =629187941167