94036996915domain: NAppears in sequencesa(n) = (6^n - 1)/5.at n=15A003464a(n) = Sum_{j=0..14} n^j.at n=6A104682a(n) = floor(A026532(n)/5).at n=30A329114a(n) = floor(A026549(n)/5).at n=30A329115