Main diagonal of triangle A100226.

Terms

a(0) =1a(1) =1a(2) =5a(3) =13a(4) =33a(5) =81a(6) =197a(7) =477a(8) =1153a(9) =2785a(10) =6725a(11) =16237a(12) =39201a(13) =94641a(14) =228485a(15) =551613a(16) =1331713a(17) =3215041a(18) =7761797a(19) =18738637a(20) =45239073a(21) =109216785a(22) =263672645a(23) =636562077a(24) =1536796801a(25) =3710155681a(26) =8957108165a(27) =21624372013a(28) =52205852193a(29) =126036076401