300874500

Appears in sequences

• Consider all compositions (ordered partitions) of n into n parts, allowing zeros. E.g., for n = 3 we get 300, 030, 003, 210, 120, 201, 102, 021, 012, 111. Then a(n) is the total number of 1's.at n=14A097070
• Row sums of the extended Catalan triangle A189231.at n=27A189911
• a(n) = (2+[n/2])*n!/((1+[n/2])*[n/2]!^2).at n=27A275329