1427440

Appears in sequences

• Expansion of (1+x)(1+x^2)/(1-x-x^3).at n=36A003410
• Expansion of (1 - x^2)/(1 - x - x^3).at n=40A058278
• Expansion of (1-x)/(1-x-2*x^2-x^3).at n=20A078007
• a(n) = Sum_{k=0..n} C(n-k, floor(k/2)).at n=37A097333
• 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=37A226275