3669866

Appears in sequences

• a(n) = Sum_{k=1..n} (2*k)!.at n=4A138524
• Array read by antidiagonals: T(m,n) = Sum(1<=i<=m) ( n + 2(i-1) )!at n=19A211368
• Number of occurrences of k in the list of transitions t(j), j <= n!-1, of interchanges a(t(j)) <-> a(t(j)+1) created by Knuth's "Algorithm T" (Plain change transitions) to generate all permutations of n distinct elements, written as a triangle T(m,k), m = n-1 >= 1, k <= m.at n=45A321668
• Partial sums of A005165.at n=10A341900