a(n,k) tabf head (staircase) for A111785 partitions of n listed in Abramowitz-Stegun order p. 831-2 (see the main page for the ref.) n\k 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 ... 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 -1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 -1 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 -1 5 -5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 -1 6 3 -21 14 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 -1 7 7 -28 -28 84 -42 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6 -1 8 8 4 -36 -72 -12 120 180 -330 132 0 0 0 0 0 0 0 0 0 0 0 7 -1 9 9 9 -45 -90 -4 -45 165 495 165 -495 -990 1287 -429 0 0 0 0 0 0 0 8 -1 10 10 10 5 -55 -110 -110 -55 -55 220 660 330 660 55 -715 -2860 -1430 2002 5005 -5005 1430 . . . n\k 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 ... ################################################################################################################## As row sequences for n=0..9: 0. [1] 1. [-1] 2. [-1,2] 3. [-1,5,-5] 4. [-1,6,3,-21,14] 5. [-1,7,7,-28,-28,84,-42] 6. [-1,8,8,4,-36,-72,-12,120,180,-330,132] 7. [-1,9,9,9,-45,-90,-45,-45,165,495,165,-495,-990,1287,-429] 8. [-1,10,10,10,5,-55,-110,-110,-55,-55,220,660,330,660,55,-715,-2860,-1430,2002,5005,-5005,1430] 9. [-1,11,11,11,11,-66,-132,-132,-66,-66,-132,-22,286,858,858,858,858,286,-1001,-4004,-2002,-6006,-1001,3003,15015,10010,-8008,-24024,19448,-4862] . . ####################################################################################################################################### The row sums are : (-1)^n, n=0..9. The unsigned row sums are : A001003(n+1) , n=0..9 ('little' Schroeder numbers). ####################################################################################################################################### Note added (Jan 30 2007): See the MathWorld entry "Series reversion", formula (11) (Morse-Feshbach). This translates into the following formula for the entries of row n pertaining to the partitions of n with m parts (in Abramowitz-Stegun order): List(n,m):= [seq(((-1)^m)*risefac(n+1,m)/((n+1)*product(e(m,k,j)!,j=1..n)),k=1..p(n,m))] with p(n,m) the number of m part partitions of n (see A008284(n,m)), risefac(n,m):= n*(n+1)*...*(n+(m-1)) (rising factorials), e(m,k,j) the exponent of j in the k-th partition of n with m part (in Abramowitz-Stegun order). The list of list of all row n entries belonging to partitions of n with m parts is then: List(n):=[seq(List(n,m),m=1..n)]. For example: n=5, m=3, produces List(5,3)= [-28, -28] corresponding to the partitions [(1^2,3),(1,2^2)]. List(5)= [[-1], [7, 7], [-28, -28], [84], [-42]]. ########################################## e.o.f ######################################################################################