270414

Appears in sequences

• Array read by antidiagonals: T(m,n) = Sum_{i=1..m} i*(n-1+i)!.at n=33A100630
• Table read by antidiagonals: T(m,n) gives the ordinal number in the table of permutations of length n+1 of the permutation which reverses the first m+1 items on a list of length n+1, leaving the remaining items unaltered. For example, T(5,7) is 28494 and the 28494th row of the permutation table of order 8 is 5 4 3 2 1 0 6 7.at n=58A100711
• Number of mutual-visibility sets in the n-Moebius ladder.at n=19A389185