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 A169732 #4 Mar 28 2020 12:57:44 %S A169732 1000,999,972,954,936,918,900,891,873,855,837,819,801,792,774,756,738, %T A169732 720,711,702,693,675,657,639,621,612,603,594,576,558,540,531,522,513, %U A169732 504,495,477,459,441,432,423,414,405,396,378,360,351,342,333,324,315,306,297,279,261,252,243,234,225,216,207,198,180,171,162,153,144,135,126,117,108,99,81,72,63,54,45,36,27,18,9,0,0,0,0,0,0,0,0,0 %N A169732 a(1) = 1000; for n>1, a(n) = a(n-1) - digitsum(a(n-1)). %p A169732 f:=proc(n) global S; option remember; if n=1 then RETURN(S) else RETURN(f(n-1)-digsum(f(n-1))); fi; end; S:=1000; [seq(f(n),n=1..120)]; %t A169732 NestList[#-Total[IntegerDigits[#]]&,1000,100] (* _Harvey P. Dale_, Mar 28 2020 *) %Y A169732 Cf. A169733, A000045, A004207, A007618, A065075, A010077, A065076, A065124, A169734, A169735. %K A169732 nonn,base %O A169732 1,1 %A A169732 _N. J. A. Sloane_, May 01 2010, based on a suggestion from Chris Cole