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A119038 Numbers n such that the n-th triangular number contains only digits {0,1,4}. 2
1, 4, 141, 144, 286, 9055, 16795, 44944, 90598, 167579, 15100424, 29678424, 45637726, 283245880, 5291767266, 1442505046119, 45042455839799, 151069595909375, 14429213707617199, 90999011435291333 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Next entry must be greater than 4.4*10^18.

LINKS

Table of n, a(n) for n=1..20.

G. Resta, Tridigital Triangular Numbers

MATHEMATICA

Select[Range[2 10^7], Complement[IntegerDigits[Binomial[# + 1, 2]], {0, 1, 4}] == {}&] (* Vincenzo Librandi, Oct 07 2015 *)

PROG

(MAGMA) [n: n in [1..2*10^7] | Set(Intseq(Binomial(n+1, 2))) subset [0, 1, 4]]; // Vincenzo Librandi, Oct 07 2015

CROSSREFS

Cf. A000217, A119037. See A119034 for a table of cross-references.

Sequence in context: A235536 A229453 A215606 * A048432 A332114 A262653

Adjacent sequences:  A119035 A119036 A119037 * A119039 A119040 A119041

KEYWORD

nonn,base

AUTHOR

Giovanni Resta, May 10 2006

EXTENSIONS

Two more terms from Max Alekseyev, Jul 11 2009

STATUS

approved

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Last modified February 26 11:49 EST 2020. Contains 332279 sequences. (Running on oeis4.)