5616324
domain: N
Appears in sequences
- a(n) = Sum_{i=0..floor(n/2)} T(i,n-i), array T as in A047072.at n=26A047074
- a(n) = (-1)^n*(2*n - 1)*CatalanNumber(n - 2) for n >= 2, a(n) = n for n = 0, 1.at n=14A078718
- Number of ways to choose three points in an (n X n)-grid (or geoplane).at n=17A178208
- a(n) = floor(n^(3/2))*floor(1 + n^(3/2))*floor(2 + n^(3/2))/6.at n=46A185592
- Quarter-square tetrahedrals: a(n) = k*(k - 1)*(k - 2)/6, k = A002620(n).at n=36A217482