OFFSET
1,2
LINKS
Giovanni Resta, Tridigital Triangular Numbers
FORMULA
MATHEMATICA
Table[Select[FromDigits/@Tuples[{1, 3, 6}, n], OddQ[Sqrt[8#+1]]&], {n, 18}]//Flatten (* Harvey P. Dale, Sep 18 2017 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, May 10 2006
EXTENSIONS
a(19)-a(21) from Tyler Busby, Mar 22 2023
STATUS
approved