1597653852domain: NAppears in sequencesa(n) = Sum_{k=0..n} binomial(k, 6*(n-k)).at n=36A293169a(n) = Sum_{k=0..n} binomial(n^2 - k,n*k).at n=6A348315Number of compositions of 7*n-1 into parts 6 and 7.at n=30A373933