a(n) = A027170(n, floor(n/2)).

Terms

a(0) =1a(1) =3a(2) =10a(3) =19a(4) =42a(5) =76a(6) =156a(7) =283a(8) =570a(9) =1046a(10) =2096a(11) =3890a(12) =7784a(13) =14582a(14) =29168a(15) =55051a(16) =110106a(17) =209062a(18) =418128a(19) =797806a(20) =1595616a(21) =3056868a(22) =6113740a(23) =11752674a(24) =23505352a(25) =45316896a(26) =90633796a(27) =175175816a(28) =350351636a(29) =678639146