Sum_{m=0..(n-1)/2} A176263(n-m-1, m).

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =-3a(5) =-2a(6) =-32a(7) =-81a(8) =-311a(9) =-810a(10) =-2515a(11) =-6864a(12) =-19944a(13) =-55043a(14) =-156023a(15) =-433522a(16) =-1217427a(17) =-3391226a(18) =-9488456a(19) =-26462205a(20) =-73933535a(21) =-206293134a(22) =-576040339a(23) =-1607642688a(24) =-4488069168a(25) =-12526662167a(26) =-34967630447