a(n) = A261236(n) - A261237(n).

Terms

a(0) =-1a(1) =0a(2) =1a(3) =2a(4) =3a(5) =6a(6) =12a(7) =28a(8) =71a(9) =186a(10) =494a(11) =1317a(12) =3478a(13) =9045a(14) =23265a(15) =59856a(16) =155779a(17) =412413a(18) =1108874a(19) =3009228a(20) =8188150a(21) =22257484a(22) =60462422a(23) =164715758a(24) =452011067a(25) =1253176571