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 A051369 #16 Mar 20 2025 04:17:36 %S A051369 3,12,21,30,39,48,57,75,93,120,129,147,165,183,210,219,246,264,300, %T A051369 309,336,363,390,399,417,453,471,489,507,534,561,579,597,624,660,678, %U A051369 714,750,768,804,831,858,885,912,939,966,993,1029,1056,1074,1101,1110,1119 %N A051369 a(n+1) = a(n) + sum of digits of a(n)^2, with a(1) = 3. %H A051369 Paolo Xausa, <a href="/A051369/b051369.txt">Table of n, a(n) for n = 1..10000</a> %t A051369 NestList[# + DigitSum[#^2] &, 3, 100] (* _Paolo Xausa_, Mar 20 2025 *) %Y A051369 Cf. A033298. %K A051369 nonn,base,easy,less %O A051369 1,1 %A A051369 Miklos SZABO (mike(AT)ludens.elte.hu)