Number of ternary words on {0,1,2} having no isolated 0's.

Terms

a(0) =1a(1) =2a(2) =5a(3) =13a(4) =33a(5) =83a(6) =209a(7) =527a(8) =1329a(9) =3351a(10) =8449a(11) =21303a(12) =53713a(13) =135431a(14) =341473a(15) =860983a(16) =2170865a(17) =5473575a(18) =13800961a(19) =34797463a(20) =87737617a(21) =221219847a(22) =557779233a(23) =1406373239a(24) =3546000945a(25) =8940814823a(26) =22543189057a(27) =56839939415a(28) =143315069777