A119210 Triangular numbers composed of digits {4,6,7}.

6, 66, 666, 476776, 764466, 4646676, 464774774646, 667474767766464747666467446, 7666777767444444644744476476, 44774674766666676747766477446

Offset

1,1

Comments

a(11) > 10^40. - Tyler Busby, Mar 29 2023

Links

Table of n, a(n) for n=1..10.

Giovanni Resta, Tridigital Triangular Numbers.

Formula

a(n) = A000217(A119211(n)). - Michel Marcus, Mar 27 2023

Crossrefs

Cf. A000217, A053957, A119211. See A119033 for a table of cross-references.

Sequence in context: A036523 A112902 A119160 * A227220 A119234 A119232

Adjacent sequences: A119207 A119208 A119209 * A119211 A119212 A119213

Keyword

nonn,base,more

Author

Giovanni Resta, May 10 2006

Status

approved