A336759 a(n) is the smallest positive number that is the sum of no fewer than n distinct repdigits.

1, 10, 21, 309, 2108, 21996, 220884, 2111105, 21866660

Offset

1,2

Comments

Conjecture: the sequence is infinite.

Links

Table of n, a(n) for n=1..9.

Example

10   is the sum of 2 distinct repdigits:                   9 + 1
21   is the sum of 3 distinct repdigits:              11 + 9 + 1
309  is the sum of 4 distinct repdigits:        222 + 77 + 9 + 1
2108 is the sum of 5 distinct repdigits: 1111 + 888 + 99 + 9 + 1
All numbers less than 10 can be summed with less than 2 distinct repdigits.
All numbers less than 21 can be summed with less than 3 distinct repdigits.

Crossrefs

Cf. A010785, A336748.

Sequence in context: A041833 A153317 A110418 * A368635 A336748 A041198

Adjacent sequences: A336756 A336757 A336758 * A336760 A336761 A336762

Keyword

nonn,base,more

Author

Falcon Shapiro, Aug 03 2020

Extensions

a(7)-a(9) from Sean A. Irvine, Aug 29 2020

Status

approved