-1270

Appears in sequences

• Expansion of (1-x)/(1+x+2*x^2-2*x^3).at n=14A078048
• Triangle read by rows, T[n,2i-1]=2T[n-1,i],T[n,2i]=2k-1-2T[n-1,i].at n=49A138583
• a(n) = Pell(n) * Sum_{d|n} (-1)^(n/d) / Pell(d), where Pell(n) = A000129(n).at n=9A204059
• Expansion of Product_{k>=1} ((1 - 4*x^k)/(1 + 4*x^k))^(1/4).at n=7A303387