47290

Appears in sequences

• Number of permutations of 2 indistinguishable copies of 1..n with exactly 4 adjacent element pairs in decreasing order.at n=4A151626
• 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=20A154283
• Beach-Williams Pell numbers of type 2pq (p,q primes).at n=14A212075