a(n) = (47^n - 1)/46.A218750a(n) = (47^n - 1)/46.Terms a(0) =0a(1) =1a(2) =48a(3) =2257a(4) =106080a(5) =4985761a(6) =234330768a(7) =11013546097a(8) =517636666560External referencesoeis: A218750