Partial sums of round(7^n/9).

Terms

a(0) =0a(1) =1a(2) =6a(3) =44a(4) =311a(5) =2178a(6) =15250a(7) =106755a(8) =747288a(9) =5231022a(10) =36617161a(11) =256320132a(12) =1794240932a(13) =12559686533a(14) =87917805738a(15) =615424640176