Number of n-step self-avoiding walks on the honeycomb lattice with no non-contiguous adjacencies.

Terms

a(0) =1a(1) =3a(2) =6a(3) =12a(4) =24a(5) =42a(6) =78a(7) =144a(8) =264a(9) =486a(10) =894a(11) =1620a(12) =2964a(13) =5376a(14) =9798a(15) =17760a(16) =32292a(17) =58398a(18) =105960a(19) =191466a(20) =346854a(21) =626172a(22) =1132800a(23) =2043246a(24) =3692406a(25) =6655068a(26) =12015126a(27) =21641526a(28) =39039810a(29) =70277016