OFFSET
1,3
COMMENTS
In other words: not counting the regions between circles.
Consider the arrangements of n circles described in A250001.
FORMULA
T(n,k) = k*A274777(n,k).
EXAMPLE
Triangle begins:
1;
0, 4, 3;
0, 0, 12, 16, 10, 6, 21;
0, 0, 0, ...
...
For n = 3 and k = 5 there are 2 arrangements of 3 circles in the affine plane forming 5 regions, excluding the regions that do not belong to the circles, so T(3,5) = 2*5 = 10.
For n = 3 and k = 6 there is only one arrangement of 3 circles in the affine plane forming 6 regions, excluding the regions that do not belong to the circles, so T(3,6) = 1*6 = 6.
Of course, there is a right triangle of all zeros starting from the second row.
CROSSREFS
KEYWORD
nonn,tabf,hard,more
AUTHOR
Omar E. Pol, Jul 07 2016
STATUS
approved