a(n) = floor(a(n-1)/(2^(1/3)-1)) with a(1)=1.

Terms

a(0) =1a(1) =3a(2) =11a(3) =42a(4) =161a(5) =619a(6) =2381a(7) =9160a(8) =35241a(9) =135583a(10) =521631a(11) =2006882a(12) =7721121a(13) =29705639a(14) =114287161a(15) =439699520a(16) =1691665681a(17) =6508382763a(18) =25039844851a(19) =96336348522a(20) =370636962881