%I A015507
%S A015507 1,1,8,352,91520,142405120,1328924579840,74403829376081920,
%T A015507 24994031979330942894080,50376471215620688640734003200,
%U A015507 609214555257707874214915513922355200
%N A015507 a(1)=1, a(n) = sum_{k=1}^{k=n-1} (6^k-1)/5 a(k).
%Y A015507 Sequence in context: A079485 A158363 A000436 this_sequence A167256 A038016 
               A072447
%Y A015507 Adjacent sequences: A015504 A015505 A015506 this_sequence A015508 A015509 
               A015510
%K A015507 nonn,easy
%O A015507 1,3
%A A015507 Olivier Gerard (olivier.gerard(AT)gmail.com)