6030140

Appears in sequences

• Number of permutations of 2 indistinguishable copies of 1..n with exactly 3 adjacent element pairs in decreasing order.at n=6A151625
• Number of permutations of 2 indistinguishable copies of 1..n with exactly 9 adjacent element pairs in decreasing order.at n=6A151631
• Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} (-1)^i * binomial(2*n+1,i) * binomial(k+2-i,2)^n, 0 <= k <= 2*(n-1).at n=39A154283
• Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} (-1)^i * binomial(2*n+1,i) * binomial(k+2-i,2)^n, 0 <= k <= 2*(n-1).at n=45A154283