(1,2,3) Jasinski-like positive power sequence.

Terms

a(0) =1a(1) =5a(2) =13a(3) =29a(4) =61a(5) =131a(6) =271a(7) =569a(8) =1381a(9) =2789a(10) =5581a(11) =11171a(12) =22369a(13) =44741a(14) =89491a(15) =185543a(16) =373273a(17) =766229a(18) =1532701a(19) =3065411a(20) =6130849a(21) =12261701a(22) =24700549a(23) =49401101a(24) =98802211a(25) =202387391a(26) =409557751a(27) =819116231a(28) =1638232471a(29) =3276464969