OFFSET
1,11
COMMENTS
Row sums are A227300.
FORMULA
r(n) = binomial(2n-k-2-3*floor(k/2), floor(k/2)), k = 0..floor((2n-1)/3). - John Molokach, Jul 29 2013
EXAMPLE
Triangle begins:
1;
1, 1;
1, 1;
1, 1, 1;
1, 1, 3, 2;
1, 1, 5, 4;
1, 1, 7, 6, 1;
1, 1, 9, 8, 6, 3;
1, 1, 11, 10, 15, 10;
1, 1, 13, 12, 28, 21, 1;
MATHEMATICA
Table[Binomial[2 n - k - 2 - 3 Floor[k/2], Floor[k/2]], {n, 1, 25}, {k, 0, Floor[(2 n - 1)/3]}] (* John Molokach, Jul 29 2013 *)
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
John Molokach, Jul 27 2013
STATUS
approved