35770

Appears in sequences

• Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1), U=(1,2), or d=(1,-1) and having abscissa of the first peak equal to k.at n=45A108438
• Triangle read by rows: T(n,k) = (2^(n+1)-1)*binomial(n,k).at n=40A134346
• G.f. B(x) satisfies: B(x) = x + 2*A(x)*C(x), where A(x) = x + C(x)*B(x) and C(x) = x + 3*A(x)*B(x).at n=7A229812
• T(n, k) = [x^k] (1/2 - x)^(-n) - (1 - x)^(-n).at n=19A356117
• Numbers k such that the sum of the proper divisors of k that have the same binary weight as k is larger than k, and no subset of these divisors sums to k.at n=20A381071