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 A169665 #17 Feb 16 2025 08:33:11 %S A169665 1,10,100,102,110,111,1000,1010,1011,1020,1100,1101,1110,1121,1122, %T A169665 1634,2000,2322,4104,5000,8208,9474,10000,10010,10011,10100,10101, %U A169665 10110,10200,10412,11000,11001,11010,11100,11210,11220,12502,12521,14758 %N A169665 Numbers divisible by the sum of 4th powers of their digits. %H A169665 Amiram Eldar, <a href="/A169665/b169665.txt">Table of n, a(n) for n = 1..10000</a> %H A169665 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Digit.html">Digit</a>. %F A169665 Numbers k such that A055013(k) | k. %e A169665 12521 is a term since 1^4 + 2^4 + 5^4 + 2^4 + 1^4 = 659, and 12521 = 19*659; %e A169665 89295 is a term since 8^4 + 9^4 + 2^4 + 9^4 + 5^4 = 17859, and 89295 = 5*17859. %p A169665 A:= proc(n) add(d^4, d=convert(n, base, 10)) ; end proc: for n from 1 to 200000 do:if irem( n,A(n))=0 then printf(`%d, `,n):else fi:od: %t A169665 Select[Range[15000], Divisible[#, Plus @@ (IntegerDigits[#]^4)] &] (* _Amiram Eldar_, Jan 31 2021 *) %Y A169665 Cf. A034087, A034088, A055013, A169666. %K A169665 nonn,base %O A169665 1,2 %A A169665 _Michel Lagneau_, Apr 05 2010