4185097

Appears in sequences

• Base 3 digits are, in order, the first n terms of the periodic sequence with initial period 2,1.at n=13A037488
• Expansion of g.f. (1+4*x)/((1-x)*(1+x)*(1-3*x)).at n=13A085287
• a(n) = (-1)^(n+1)*(3/4)*(9^n-1)*B(2*n) where B(k) denotes the k-th Bernoulli number.at n=7A090643