W. Lang, Sep 19 2008 a(n,m) tabl head (triangle) for A144351 = S1hat(1) n\m 1 2 3 4 5 6 7 8 9 10 ... 1 1 0 0 0 0 0 0 0 0 0 2 1 1 0 0 0 0 0 0 0 0 3 2 1 1 0 0 0 0 0 0 0 4 6 3 1 1 0 0 0 0 0 0 5 24 8 3 1 1 0 0 0 0 0 6 120 34 9 3 1 1 0 0 0 0 7 720 156 36 9 3 1 1 0 0 0 8 5040 924 166 37 9 3 1 1 0 0 9 40320 6144 968 168 37 9 3 1 1 0 10 362880 48096 6372 978 169 37 9 3 1 1 . . . The row sums give A107107: [1,1,2,4,11,37,168,926,6181,47651,...]. The first thre rows are A000142(n-1) = (n-1)!, A144352, A144353. ################################# e.o.f. #####################################