OFFSET
1,2
MATHEMATICA
Do[k = FromDigits[ RotateRight[ IntegerDigits[n(n + 1)/2]]]; l = Floor[ Sqrt[2k]]; If[k == l(l + 1)/2, Print[n(n + 1)/2]], {n, 1, 10^5}]
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Robert G. Wilson v, Feb 28 2002
STATUS
approved