A119156 Triangular numbers composed of digits {2,3,8}.

3, 28, 3828, 828828, 388333828828, 223832333328828, 332828222833288828828, 28388332838238232223328828

Offset

1,1

Comments

a(9) > 10^45. - Tyler Busby, Mar 29 2023

Links

Table of n, a(n) for n=1..8.

Giovanni Resta, Tridigital Triangular Numbers.

Formula

a(n) = A000217(A119157(n)). - Tyler Busby, Mar 29 2023

Prog

(Python)
klimit = 10**6
A000217 = (k*(k+1)//2 for k in range(klimit)) # generator
print([m for m in A000217 if set(str(m)) <= set("238")]) # Michael S. Branicky, Mar 28 2021

Crossrefs

Cf. A000217, A119157. See A119033 for a table of cross-references.

Sequence in context: A196735 A208438 A122891 * A175979 A096621 A362466

Adjacent sequences: A119153 A119154 A119155 * A119157 A119158 A119159

Keyword

nonn,base,more

Author

Giovanni Resta, May 10 2006

Status

approved