3179520

Appears in sequences

• a(n) = n!*2^(n+1) * (Integral_{x = 0..1} 1/(1+x^2)^(n+1) dx) - Pi*(2*n)!/(2^(n+1)*n!).at n=8A087547
• Number of n X n binary arrays without the pattern 1 1 0 diagonally or antidiagonally.at n=4A189104
• Number of nX5 binary arrays without the pattern 1 1 0 diagonally or antidiagonally.at n=4A189107
• T(n,k)=Number of nXk binary arrays without the pattern 1 1 0 diagonally or antidiagonally.at n=40A189111
• Number of 5Xn binary arrays without the pattern 1 1 0 diagonally or antidiagonally.at n=4A189113
• Triangle read by rows: T(n,k) is the number of linear chord diagrams on 2n vertices with one marked chord such that exactly k of the remaining n-1 chords are excluded by (i.e., are outside and do not contain) the marked chord.at n=28A336601