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A336748
a(n) is the smallest number that is the sum of at least n repdigits (not necessarily distinct) but not of any fewer.
2
1, 10, 21, 320, 2219, 32218, 332217, 3332216, 33332215, 333332214, 3333332213
OFFSET
1,2
COMMENTS
I believe the sequence is infinite.
a(10) exists and is <= 333332214.
EXAMPLE
1 is the sum of 1 repdigit: 1;
10 is the sum of 2 repdigits: 9 + 1;
21 is the sum of 3 repdigits: 11 + 9 + 1;
320 is the sum of 4 repdigits: 222 + 88 + 9 + 1;
2219 is the sum of 5 repdigits: 1111 + 999 + 99 + 9 + 1;
32218 is the sum of 6 repdigits: 22222 + 8888 + 999 + 99 + 9 + 1;
332217 is the sum of 7 repdigits: 222222 + 99999 + 8888 + 999 + 99 + 9 + 1.
All numbers less than 10 can be summed with less than 2 repdigits.
All numbers less than 21 can be summed with less than 3 repdigits. etc.
PROG
(C++) See Links section.
CROSSREFS
Cf. A000325 (binary analog, see A100661), A010785.
Sequence in context: A110418 A336759 A368635 * A041198 A035318 A039821
KEYWORD
nonn,base,more
AUTHOR
Falcon Shapiro, Aug 02 2020
EXTENSIONS
a(8) from Jinyuan Wang, Aug 03 2020
a(9) from David A. Corneth, Aug 03 2020
a(10)-a(11) from Rémy Sigrist, Aug 25 2022
STATUS
approved