A119198 Triangular numbers composed of digits {3,6,9}.

3, 6, 36, 66, 666, 333336, 936396, 963966, 3966336, 3996939936, 99363693366, 63666996693966, 339666999336666, 633636693339936, 39696699699366996, 999699963339963966, 36936333639936696636, 6933666366666339963969663666, 393996396333933393393669696696, 399693363966633933999339639336

Offset

1,1

Links

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

Giovanni Resta, Tridigital Triangular Numbers.

Formula

a(n) = A000217(A119199(n)). - Tyler Busby, Mar 26 2023

Crossrefs

Cf. A000217, A053949, A119199. See A119033 for a table of cross-references.

Sequence in context: A119063 A119154 A119194 * A119196 A119184 A350991

Adjacent sequences: A119195 A119196 A119197 * A119199 A119200 A119201

Keyword

nonn,base

Author

Giovanni Resta, May 10 2006

Extensions

a(19)-a(20) from Tyler Busby, Mar 26 2023

Status

approved