

A233795


Number of triangular numbers between triangular(n) and n^2.


0



0, 0, 0, 0, 1, 1, 1, 2, 2, 3, 3, 4, 4, 4, 5, 5, 6, 6, 6, 7, 7, 8, 8, 9, 9, 9, 10, 10, 11, 11, 11, 12, 12, 13, 13, 13, 14, 14, 15, 15, 16, 16, 16, 17, 17, 18, 18, 18, 19, 19, 20, 20, 21, 21, 21, 22, 22, 23, 23, 23, 24, 24, 25, 25, 26, 26, 26, 27, 27, 28, 28, 28, 29, 29
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OFFSET

0,8


COMMENTS

Number of triangular numbers t such that n*(n+1)/2 < t < n^2.


LINKS



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

Cf. A022846 (number of triangular numbers less than n^2).


KEYWORD

nonn


AUTHOR



STATUS

approved



