This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A061772 #21 Aug 18 2024 02:01:20 %S A061772 10,45,300,2250,18000,150000,1285714,11250000,100000000,900000000, %T A061772 8181818181,75000000000,692307692307,6428571428572,60000000000000, %U A061772 562500000000000,5294117647058823,50000000000000000,473684210526315789,4500000000000000000,42857142857142857143 %N A061772 a(n) is the number of n-digit multiples of n. %F A061772 a(n) = floor(9*10^(n-1)/n) or floor(9*10^(n-1)/n) + 1. %F A061772 a(1)=10; a(n) = floor((10^n - 1)/n) - floor((10^(n-1) - 1)/n) for n > 1. - _Jon E. Schoenfield_, Dec 02 2021 %e A061772 a(3) = 300 as there are 300 3-digit numbers divisible by 3: 102, 105, ..., 999. %K A061772 nonn,base,easy %O A061772 1,1 %A A061772 _Amarnath Murthy_, May 23 2001 %E A061772 More terms from _Jason Earls_, May 26 2001 %E A061772 More terms and a(14) corrected by _Jon E. Schoenfield_, Dec 02 2021