OFFSET
1,1
COMMENTS
For n > 2, A309597(n) is a term. - Seiichi Manyama, Sep 15 2019
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..51
EXAMPLE
300 is triangular and contains the digits 0 and 3.
MATHEMATICA
Select[Accumulate[Range[14000]], Count[DigitCount[#], Except[0]]==2&] (* Harvey P. Dale, Nov 27 2011 *)
PROG
(PARI) for(k=0, 1e5, if(#Set(digits(j=k*(k+1)/2))==2, print1(j", "))) \\ Seiichi Manyama, Sep 15 2019
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Erich Friedman, Jul 04 2001
STATUS
approved