6501577152domain: NAppears in sequencesNumber of permutations of 4 indistinguishable copies of 1..n with exactly 5 adjacent element pairs in decreasing order.at n=4A151643Irregular triangle read by rows: T(n,k) = Sum_{i=0..k} (-1)^i * binomial(4*n+1,i) * binomial(k+4-i,4)^n, 0 <= k <= 4*(n-1).at n=33A236463