a(n) = A188491(n-1) + A188495(n-1) + A188497(n-1).

Terms

a(0) =0a(1) =0a(2) =2a(3) =6a(4) =14a(5) =31a(6) =104a(7) =344a(8) =1084a(9) =3236a(10) =9784a(11) =29964a(12) =92241a(13) =282780a(14) =865064a(15) =2646292a(16) =8102454a(17) =24813838a(18) =75982346a(19) =232630527a(20) =712230076a(21) =2180675264a(22) =6676819512a(23) =20443032008a(24) =62591840320a(25) =191641545768a(26) =586762729889