169766

Appears in sequences

• Number of ways of choosing at most n-1 items from a set of size 2*n+1.at n=9A008549
• a(n) = Sum_{k=0..8} binomial(n,k).at n=19A008861
• A convolution triangle of numbers, generalizing Pascal's triangle A007318.at n=46A035324
• a(n) = 2^(n-1) - binomial(n, floor(n/2)).at n=18A093387
• Riordan matrix (1/(1-4x),(1-sqrt(1-4x))/2).at n=57A187926
• a(n) = 2^(n-1) + ((1+(-1)^n)/4)*binomial(n, n/2) - binomial(n, floor(n/2)).at n=19A294175