a(n) = (43^n - 1)/42.A218746a(n) = (43^n - 1)/42.Terms a(0) =0a(1) =1a(2) =44a(3) =1893a(4) =81400a(5) =3500201a(6) =150508644a(7) =6471871693a(8) =278290482800External referencesoeis: A218746