A255678 Smallest number m needing exactly n distinct digits in decimal representation of m*(m+1)/2.

0, 4, 14, 45, 143, 452, 1431, 4549, 14334, 46097

Offset: 1

Author

Reinhard Zumkeller, Jul 11 2015

Keywords

• nonn
• base
• fini
• full

Comments

A118668(a(n)) = n and A118668(m) <> n for m < a(n).

Crossrefs

Cf. A118668, A260214 (the resulting triangular numbers).

Programs

Haskell

a255678 n = head $ filter ((== n) . a118668) [0..]