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

1,2

Comments

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

Links

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

Prog

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

Crossrefs

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

Sequence in context: A005775 A094688 A068092 * A153480 A229007 A232060

Adjacent sequences: A255675 A255676 A255677 * A255679 A255680 A255681

Keyword

nonn,base,fini,full

Author

Reinhard Zumkeller, Jul 11 2015

Status

approved