966751

Properties

Appears in sequences

• a(n) = Sum_{ composite k, 1 <= k <= 10^n} (Number of divisors d of k with 1 < d < k).at n=4A136364
• Number of n X 5 arrays with rows being permutations of 0..4 and no column j greater than column j-1 in all rows.at n=2A212852
• T(n,k) = number of n X k arrays with rows being permutations of 0..k-1 and no column j greater than column j-1 in all rows (n, k >= 1).at n=23A212855
• Number of 3 X n arrays with rows being permutations of 0..n-1 and no column j greater than column j-1 in all rows.at n=5A212856
• Triangle read by rows, (Sum_{k=0..n} T[n,k]*x^k) / (1-x)^(n+1) are generating functions of the columns of A287698.at n=20A287697
• Triangle read by rows: T(n,k) is the number of ordered triples of n-permutations with exactly k common descents, n>=0, 0<=k<=max(0,n-1).at n=11A334394
• Prime numbersat n=76119