Row sums of triangle A171840.

Terms

a(0) =1a(1) =3a(2) =8a(3) =22a(4) =68a(5) =241a(6) =974a(7) =4410a(8) =21969a(9) =118698a(10) =688301a(11) =4250788a(12) =27795353a(13) =191545796a(14) =1385868437a(15) =10493852359a(16) =82932266786a(17) =682421525516