OFFSET
1,5
LINKS
The IBM Ponder This July 2013 challenge asks for A(8,3).
EXAMPLE
Three tetrahedra labeled (1, 2, 8, 12) yield the 20 possible sums 3, 4, 5, 6, 10, 11, 12, 14, 15, 16, 17, 18, 21, 22, 24, 25, 26, 28, 32, 36. No more sums can be obtained by different labelings, and no labeling with labels < 12 yields 20 possible sums. Therefore A(4,3) = 12.
Square array A(n,k) begins:
1, 1, 1, 1, 1, 1, 1, 1, ...
1, 2, 2, 2, 2, 2, 2, ...
1, 3, 4, 5, 6, 7, ...
1, 4, 7, 12, 16, ...
1, 5, 12, 24, ...
1, 6, 18, ...
1, 7, ...
1, ...
CROSSREFS
KEYWORD
AUTHOR
Jens Voß, Jul 17 2013
STATUS
approved