239666

Appears in sequences

• a(n) = number of (s(0), s(1), ..., s(2*n-1)) such that s(i) is a nonnegative integer and |s(i) - s(i-1)| = 1 for i = 1,2,...,n, s(0) = 2, s(2*n-1) = 5. Also a(n) = T(2*n-1,n-2), where T is the array defined in A026009.at n=9A026017
• Expansion of 1 + 2/(1-2*x-x^3).at n=16A052910
• Expansion of (1+x*C)*C^3, where C = (1-sqrt(1-4*x))/(2*x) is g.f. for Catalan numbers, A000108.at n=10A070031
• Number of nondecreasing integer sequences of length 29 with sum zero and sum of absolute values 2n.at n=18A158163