4992240domain: NAppears in sequencesFibonacci sequence beginning 0, 6.at n=30A022089Expansion of (1+3x+x^2)/(1-3x+x^2).at n=15A099857Number of length-n ternary strings x with the property that if w is a subword of x and |w| >= 3, then w reversed is not a subword of x.at n=29A330010a(n) = n*(n+1)*(n+2)*(n+3)*(2*n+1)/12.at n=30A356251