2490367domain: NAppears in sequencesa(n) = (n+1)*2^(n-1) - 1.at n=17A099035Number of chains in the power set lattice, or the number of fuzzy subsets of an (n+4)-element set X_(n+4) with specification n elements of one kind, 3 elements of another and 1 of yet another kind.at n=8A107954a(n) = 19*2^n-1.at n=17A198276