Column 1 of triangle A134090.

Terms

a(0) =1a(1) =2a(2) =9a(3) =46a(4) =285a(5) =2021a(6) =16023a(7) =139812a(8) =1326111a(9) =13544857a(10) =147880458a(11) =1715413558a(12) =21036674321a(13) =271585117428