4870878domain: NAppears in sequencesLet S(1) = {1} and, for n>1 let S(n) be the smallest set containing x, 2x and x+2 for each element x in S(n-1). a(n) is the number of elements in S(n).at n=31A122554a(n) = n + 2*cos((n*Pi)/3) + Lucas(n).at n=31A297661Number of chordless cycles in the n-web graph.at n=29A297665