A119129 Numbers k such that the k-th triangular number contains only digits {1,4,8}.

1, 478, 1541, 4866, 988113, 4216353, 15155321, 16977521, 983990258, 531956543121, 544826911685686, 16843306612090658, 127392946577229686

Offset

1,2

Comments

Next term exceeds 1.4*10^20.

Links

Table of n, a(n) for n=1..13.

G. Resta, Tridigital Triangular Numbers

Crossrefs

Cf. A000217, A119128. See A119034 for a table of cross-references.

Sequence in context: A252544 A252545 A260204 * A252542 A122268 A186950

Adjacent sequences: A119126 A119127 A119128 * A119130 A119131 A119132

Keyword

nonn,base,more

Author

Giovanni Resta, May 10 2006

Extensions

a(12)-a(13) from Max Alekseyev, Aug 16 2013

Status

approved