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 A177262 Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} starting with exactly k consecutive integers (1<=k<=n). 0
 1, 1, 1, 4, 1, 1, 18, 4, 1, 1, 96, 18, 4, 1, 1, 600, 96, 18, 4, 1, 1, 4320, 600, 96, 18, 4, 1, 1, 35280, 4320, 600, 96, 18, 4, 1, 1, 322560, 35280, 4320, 600, 96, 18, 4, 1, 1, 3265920, 322560, 35280, 4320, 600, 96, 18, 4, 1, 1, 36288000, 3265920, 322560, 35280, 4320 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS Sum of entries in row n is n!. T(n,1)=A094258(n)=(n-1)!(n-1). Sum(k*T(n,k), k=1..n)=1!+2!+...+n!=A007489(n). LINKS FORMULA T(n,k)=(n-k)!(n-k) if k

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Last modified November 28 01:24 EST 2021. Contains 349396 sequences. (Running on oeis4.)