A119158 Triangular numbers composed of digits {2,4,5}.

45, 55, 25425, 255255, 22542255, 244525555, 2245524452445, 2445254445525, 5255545252454245, 444222245455224445, 4544525455555255444225, 5554545454254522254255544522452525245

Offset: 1

Author

Giovanni Resta, May 10 2006

Keywords

• nonn
• base
• more

Comments

a(13) > 10^40.

Links

• G. Resta, Tridigital Triangular Numbers.

Crossrefs

Cf. A000217, A031152, A119159. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119159(n)).

Extensions

a(12) from Max Alekseyev, Aug 19 2013