A modified Legendre-binomial transform of 2^n for p=3.

Terms

a(0) =1a(1) =2a(2) =13a(3) =26a(4) =52a(5) =338a(6) =757a(7) =1514a(8) =9841a(9) =19682a(10) =39364a(11) =255866a(12) =511732a(13) =1023464a(14) =6652516a(15) =14899274a(16) =29798548a(17) =193690562a(18) =387440173a(19) =774880346a(20) =5036722249a(21) =10073444498a(22) =20146888996a(23) =130954778474a(24) =293292210961a(25) =586584421922