login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A119052
Numbers k such that the k-th triangular number contains only digits {0,2,5}.
3
10, 100, 224, 714, 1000, 10000, 32410, 67089, 100000, 210010, 1000000, 1019825, 2100010, 2109599, 3231100, 10000000, 21000010, 33173785, 71450010, 100000000, 200101000, 201000100, 210000010, 663702049, 1000000000
OFFSET
1,1
MATHEMATICA
Select[Range[2 10^7], Complement[IntegerDigits[Binomial[# + 1, 2]], {0, 2, 5}] == {}&] (* Vincenzo Librandi, Oct 07 2015 *)
PROG
(Magma) [n: n in [1..2*10^7] | Set(Intseq(Binomial(n+1, 2))) subset [0, 2, 5]]; // Vincenzo Librandi, Oct 07 2015
CROSSREFS
Cf. A000217, A119051. See A119034 for a table of cross-references.
Sequence in context: A101655 A043216 A044342 * A029774 A208375 A208065
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, May 10 2006
STATUS
approved