Second diagonal of Gely numbers.

Terms

a(0) =0a(1) =1a(2) =0a(3) =5a(4) =6a(5) =21a(6) =36a(7) =85a(8) =162a(9) =341a(10) =672a(11) =1365a(12) =2718a(13) =5461a(14) =10908a(15) =21845a(16) =43674a(17) =87381a(18) =174744a(19) =349525a(20) =699030a(21) =1398101a(22) =2796180a(23) =5592405a(24) =11184786a(25) =22369621a(26) =44739216a(27) =89478485a(28) =178956942a(29) =357913941