OFFSET
0,8
COMMENTS
Number of triangular numbers t such that n*(n+1)/2 < t < n^2.
MATHEMATICA
nn = 110; tri = Table[n (n + 1)/2, {n, nn}]; mx = Floor[Sqrt[tri[[-1]]]]; Join[{0}, Table[Length[Intersection[tri, Range[tri[[n]] + 1, n^2 - 1]]], {n, mx}]] (* T. D. Noe, Dec 20 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alex Ratushnyak, Dec 16 2013
STATUS
approved