OFFSET
1,1
LINKS
Giovanni Resta, Tridigital Triangular Numbers
FORMULA
MATHEMATICA
Rest[Select[FromDigits/@Tuples[{0, 5, 6}, 15], IntegerQ[(Sqrt[8#+1]-1)/2]&]] (* Harvey P. Dale, Nov 19 2013 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, May 10 2006
EXTENSIONS
a(23)-a(24) from Tyler Busby, Mar 22 2023
STATUS
approved