150178

Appears in sequences

• Number of down-up permutations of n+4 starting with 4.at n=8A006216
• Read across rows of Euler-Bernoulli or Entringer triangle.at n=38A008283
• a(n) = Sum_{k=0..n} T(n,k) * T(n,n+k), with T given by A027023.at n=9A027046