1085822640

Appears in sequences

• a(n) = (2n+3)!/(n!*(n+2)!).at n=13A000917
• Number of sequences {s(i): i=0..n} such that |s(i)-s(i-1)|=1, i=1..n and s(i)=0 at four values of i, one of which is i=0.at n=32A052207
• Number of valleys in all left factors of Dyck paths of length n. A valley is a (1,-1)-step followed by a (1,1)-step.at n=30A191522
• Number of turns in all left factors of Dyck paths of length n.at n=29A191527
• a(n) = (n!*m)/(m!*(m+1)!) where m = floor(n/2).at n=29A237884