cp's OEIS Frontend

A336748 a(n) is the smallest number that is the sum of at least n repdigits (not necessarily distinct) but not of any fewer.

%I A336748 #38 Jan 29 2023 20:26:07
%S A336748 1,10,21,320,2219,32218,332217,3332216,33332215,333332214,3333332213
%N A336748 a(n) is the smallest number that is the sum of at least n repdigits (not necessarily distinct) but not of any fewer.
%C A336748 I believe the sequence is infinite.
%C A336748 a(10) exists and is <= 333332214.
%H A336748 Rémy Sigrist, <a href="/A336748/a336748.txt">C++ program</a>
%e A336748 1      is the sum of 1 repdigit: 1;
%e A336748 10     is the sum of 2 repdigits: 9      + 1;
%e A336748 21     is the sum of 3 repdigits: 11     + 9     + 1;
%e A336748 320    is the sum of 4 repdigits: 222    + 88    + 9    + 1;
%e A336748 2219   is the sum of 5 repdigits: 1111   + 999   + 99   + 9   + 1;
%e A336748 32218  is the sum of 6 repdigits: 22222  + 8888  + 999  + 99  + 9  + 1;
%e A336748 332217 is the sum of 7 repdigits: 222222 + 99999 + 8888 + 999 + 99 + 9 + 1.
%e A336748 All numbers less than 10 can be summed with less than 2 repdigits.
%e A336748 All numbers less than 21 can be summed with less than 3 repdigits. etc.
%o A336748 (C++) See Links section.
%Y A336748 Cf. A000325 (binary analog, see A100661), A010785.
%K A336748 nonn,base,more
%O A336748 1,2
%A A336748 _Falcon Shapiro_, Aug 02 2020
%E A336748 a(8) from _Jinyuan Wang_, Aug 03 2020
%E A336748 a(9) from _David A. Corneth_, Aug 03 2020
%E A336748 a(10)-a(11) from _Rémy Sigrist_, Aug 25 2022