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 A230102 #13 Aug 06 2024 09:05:38 %S A230102 1,2,4,8,16,22,26,38,62,74,102,102,102,102,102,102,102,102,102,102, %T A230102 102,102,102,102,102,102,102,102,102,102,102,102,102,102,102,102,102, %U A230102 102,102,102,102,102,102,102,102,102,102,102,102,102,102 %N A230102 a(0)=1; thereafter a(n+1) = a(n) + (product of digits of a(n)). %C A230102 Never gets above 102. %H A230102 <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a> %H A230102 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1). %t A230102 NestList[#+Times@@IntegerDigits[#]&,1,50] (* _Harvey P. Dale_, Jul 30 2023 *) %o A230102 (Haskell) %o A230102 a230102 n = a230102_list !! n %o A230102 a230102_list = iterate a230099 1 -- _Reinhard Zumkeller_, Oct 13 2013 %Y A230102 Cf. A007954, A051801, A063108, A230099, A232485. %K A230102 nonn,base %O A230102 0,2 %A A230102 _N. J. A. Sloane_, Oct 12 2013