OFFSET
1,3
MATHEMATICA
With[{trnos=Accumulate[Range[100]]}, Table[Count[trnos, _?(n<=#<=2n&)], {n, 110}]] (* Harvey P. Dale, Jul 23 2013 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Amarnath Murthy, Jason Earls, Jul 22 2003
STATUS
approved