4493437

Appears in sequences

• Expansion of (1+x)(1+x^2)/(1-x-x^3).at n=39A003410
• Expansion of (1 - x^2)/(1 - x - x^3).at n=43A058278
• a(n) = Sum_{k=0..n} C(n-k, floor(k/2)).at n=40A097333
• a(0) = 1, a(1) = 2, a(2) = 5; for n >= 3, a(n) = a(n-1) + 2*a(n-2) + a(n-3).at n=20A101399
• Number of new rationals produced at the n-th iteration by applying the map t -> {t+1, -1/t} to nonzero terms, starting with S[0] = {1}.at n=40A226275