A119050 Numbers k such that the k-th triangular number contains only digits {0,2,3}.

2, 24, 77, 215, 637, 802, 8002, 25815, 80002, 800002, 2158797, 8000002, 25768322, 66382562, 80000002, 800000002, 8000000002, 21596311362, 80000000002, 800000000002, 8000000000002, 80000000000002, 800000000000002

Offset

1,1

Links

Table of n, a(n) for n=1..23.

G. Resta, Tridigital Triangular Numbers

Mathematica

Select[Range[3 10^7], Complement[IntegerDigits[Binomial[# + 1, 2]], {0, 2, 3}] == {}&] (* Vincenzo Librandi, Oct 07 2015 *)

Prog

(Magma) [n: n in [1..2*10^7] | Set(Intseq(Binomial(n+1, 2))) subset [0, 2, 3]]; // Vincenzo Librandi, Oct 07 2015

Crossrefs

Cf. A000217, A119049. See A119034 for a table of cross-references.

Sequence in context: A003614 A195189 A119060 * A119068 A068379 A136280

Adjacent sequences: A119047 A119048 A119049 * A119051 A119052 A119053

Keyword

nonn,base

Author

Giovanni Resta, May 10 2006

Status

approved