OFFSET
0,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
MATHEMATICA
Do[ If[ IntegerQ[ Apply[ Plus, IntegerDigits[n(n + 1)/2]] / Floor[ Log[10, n(n + 1)/2] + 1]], Print[n(n + 1)/2]], {n, 1, 10^3}]
Select[Accumulate[Range[200]], IntegerQ[Mean[IntegerDigits[#]]]&] (* Harvey P. Dale, Jun 17 2017 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Apr 08 2002
EXTENSIONS
Edited and extended by Robert G. Wilson v, Apr 12 2002
STATUS
approved