First differences of A063843.

Terms

a(0) =1a(1) =33a(2) =758a(3) =9896a(4) =79317a(5) =443353a(6) =1904490a(7) =6718440a(8) =20366673a(9) =54770809a(10) =133699830a(11) =301347872a(12) =635317397a(13) =1265529825a(14) =2400903226a(15) =4365984432a(16) =7650100929a(17) =12972006129a(18) =21363430102a(19) =34275416568a(20) =53711825909