Number of self-avoiding walks of length n on an infinite triangular prism starting at the origin.

Terms

a(0) =1a(1) =4a(2) =12a(3) =34a(4) =90a(5) =222a(6) =542a(7) =1302a(8) =3058a(9) =7186a(10) =16714a(11) =38670a(12) =89358a(13) =205710a(14) =472906a(15) =1086138a(16) =2491666a(17) =5713318a(18) =13094950a(19) =30003190a(20) =68731010a(21) =157423986a(22) =360530346a(23) =825626942a(24) =1890615518a(25) =4329196974a(26) =9912914314a(27) =22698017834a(28) =51972012258a(29) =119000208806