215233604domain: NAppears in sequencesa(n) = n*3^n - 1.at n=14A060352Sequence of sums of alternating powers of 3.at n=33A079362Expansion of (1+2x-x^3+x^4)/(1-4x^2+3x^4).at n=34A181655a(n) = 5*3^n-1.at n=16A198643a(n) = 5*9^n-1.at n=8A198962