45699447

Appears in sequences

• Number of permutations of 3 indistinguishable copies of 1..n with exactly 3 adjacent element pairs in decreasing order.at n=5A151633
• Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} (-1)^i * binomial(3*n+1,i) * binomial(k+3-i,3)^n, 0 <= k <= 3*(n-1).at n=38A174266
• Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} (-1)^i * binomial(3*n+1,i) * binomial(k+3-i,3)^n, 0 <= k <= 3*(n-1).at n=47A174266