489510

Appears in sequences

• A partition product of Stirling_2 type [parameter k = 1] with biggest-part statistic (triangle read by rows).at n=41A157401
• Triangular array read by rows: T(n,k) is the number of f:{1,2,...,n}->{1,2,...,n} with exactly 2k elements that have a preimage of even (possibly zero) cardinality; n>=0, 0<=k<=floor(n/2).at n=18A225942