OFFSET
0,2
COMMENTS
FORMULA
T(n,k) = 3k (0 <= k <= n-1), T(n,k) = 12n-3k-3 (n <= k <= 2n-1), T(n,2n) = 3n+1.
EXAMPLE
Triangle begins:
[1]
[3, 6, 4]
[3, 6, 15, 12, 7]
[3, 6, 9, 24, 21, 18, 10]
[3, 6, 9, 12, 33, 30, 27, 24, 13]
[3, 6, 9, 12, 15, 42, 39, 36, 33, 30, 16]
[3, 6, 9, 12, 15, 18, 51, 48, 45, 42, 39, 36, 19]
[3, 6, 9, 12, 15, 18, 21, 60, 57, 54, 51, 48, 45, 42, 22]
...
Example. Suppose n = 2. We find:
triple count pair-sums 0 1 2 3 4
-------------
002 3 0,2 3 3
012 6 1,2,3 6 6 6
112 3 2,3 3 3
022 3 2,4 3 3
122 3 3,4 3 3
222 1 4 1
-------------
Totals: 3 6 15 12 7, which is row 2 of the triangle.
MAPLE
See A245556.
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
N. J. A. Sloane, Aug 04 2014
STATUS
approved