a(n) = Sum_{k=0..n} (k+1) * A026769(n, k).

Terms

a(0) =1a(1) =3a(2) =8a(3) =22a(4) =55a(5) =143a(6) =349a(7) =885a(8) =2138a(9) =5356a(10) =12890a(11) =32092a(12) =77178a(13) =191530a(14) =460934a(15) =1141888a(16) =2751551a(17) =6809421a(18) =16431189a(19) =40633227a(20) =98175341a(21) =242626935a(22) =586867463a(23) =1449457735a(24) =3509084995a(25) =8661201115a(26) =20982916461a(27) =51755457003