188480domain: NAppears in sequencesNumber of compositions of 7*n-2 into parts 6 and 7.at n=18A373934a(n) = Sum_{k=0..floor(n/2)} binomial(k+2,3*n-6*k+2).at n=39A390035Expansion of 1 / ((1-x)^6 - x^7).at n=16A392547