OFFSET
1,6
LINKS
Eric Weisstein's World of Mathematics, Chromatic Invariant
Eric Weisstein's World of Mathematics, Complete Bipartite Graph
FORMULA
T(m,n) = Sum_{k = 0..m-1} k!*(-1)^(k + m)*(k + 1)^n*Stirling2(m, k + 2) for max(m,n) > 1.
EXAMPLE
Triangle begins:
1
0 1
0 1 5
0 1 13 73
0 1 29 301 2069
MATHEMATICA
Join[{1}, Table[Sum[k! (-1)^(k + m) (k + 1)^n StirlingS2[m, k + 2], {k, 0, m - 1}], {n, 2, 10}, {m, n}]] // Flatten
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Eric W. Weisstein, Aug 31 2017
STATUS
approved