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A211369
Array read by antidiagonals: T(m,n) = m*(m+n-1)! + Sum( n <= i <= m+n-2 ) i!
2
1, 2, 5, 6, 14, 21, 24, 54, 80, 105, 120, 264, 390, 512, 633, 720, 1560, 2304, 3030, 3752, 4473, 5040, 10800, 15960, 21024, 26070, 31112, 36153, 40320, 85680, 126720, 167160, 207504, 247830, 288152, 328473, 362880, 766080, 1134000
OFFSET
1,2
COMMENTS
Index numbers (compare A055089) of transpositions.
LINKS
Tilman Piesk, Arrays of permutations (Wikiversity)
FORMULA
T(m,1) = A001563(m) + A007489(m-1). - R. J. Mathar, May 11 2013
EXAMPLE
T(3,2) = 3*4! + Sum( 2 <= i <= 3 ) i!
= 3*4! + 2! + 3!
= 3*24 + 2 + 6 = 80.
The array starts:
1, 2, 6, 24, 120,...
5, 14, 54, 264, 1560,...
21, 80, 390, 2304, 15960,...
105, 512, 3030, 21024,167160,...
633, 3752, 26070,207504,1860600,...
MAPLE
A211369 := proc(m, n)
m*(m+n-1)!+add(i!, i=n..m+n-2) ;
end proc: # R. J. Mathar, May 10 2013
CROSSREFS
Cf. A055089, A000142 (row 1), A052649 (row 2)
Sequence in context: A191229 A191120 A245540 * A006596 A000092 A100630
KEYWORD
nonn,tabl
AUTHOR
Tilman Piesk, Jul 07 2012
STATUS
approved