1-sequence of reduction of (3n) by x^2 -> x+1.

Terms

a(0) =0a(1) =6a(2) =15a(3) =39a(4) =84a(5) =174a(6) =342a(7) =654a(8) =1221a(9) =2241a(10) =4056a(11) =7260a(12) =12876a(13) =22662a(14) =39627a(15) =68907a(16) =119244a(17) =205482a(18) =352770a(19) =603630a(20) =1029825a(21) =1752261a(22) =2974320a(23) =5037624a(24) =8515224a(25) =14367174a(26) =24200007a(27) =40699119a(28) =68348676a(29) =114629286