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

Terms

a(0) =0a(1) =5a(2) =43a(3) =309a(4) =2176a(5) =15248a(6) =106752a(7) =747285a(8) =5231019a(9) =36617157a(10) =256320128a(11) =1794240928a(12) =12559686528a(13) =87917805733a(14) =615424640171