OFFSET
1,1
COMMENTS
1. The sequence is unbounded, as the (2*10^k +3)-th triangular number is a term. 2. The sum of the digits of triangular numbers in most cases is a triangular number. 3. Conjecture: For every triangular number T there exist infinitely many triangular numbers with sum of digits = T.
MATHEMATICA
Select[Accumulate[Range[300]], Total[IntegerDigits[#]]==15&] (* Harvey P. Dale, Oct 09 2012 *)
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Amarnath Murthy, Feb 21 2002
EXTENSIONS
More terms from Sascha Kurz, Mar 06 2002
STATUS
approved