OFFSET
3,2
COMMENTS
FORMULA
T(n,k) = k*C(n,k+1) - C(n,k) + 1
EXAMPLE
Triangle (beginning with n=3, k=1) is:
1
3 3
6 11 6
10 26 26 10
15 50 71 50 15
e.g. n=5, k = 2, T(5,2) = 11 = permutations of [5] with first run 2 long and last run 5-2-1 = 2 long, namely {14325, 15324, 15423, 24315, 25314, 25413, 34215, 35214, 35412, 45213, 45312}
CROSSREFS
KEYWORD
AUTHOR
David Scambler, Nov 22 2006
STATUS
approved