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 A055565 #26 Jul 02 2025 16:01:59
%S A055565 0,1,7,9,13,13,18,7,19,18,1,16,18,22,22,18,25,19,27,10,7,27,22,31,27,
%T A055565 25,37,18,28,25,9,22,31,27,25,19,36,28,25,18,13,31,27,25,37,18,37,43,
%U A055565 27,31,13,27,25,37,27,28,43,18,31,22,18,34,37,36,37,34,45,13,31,27,7
%N A055565 Sum of digits of n^4.
%H A055565 Seiichi Manyama, <a href="/A055565/b055565.txt">Table of n, a(n) for n = 0..10000</a>
%F A055565 a(n) = A007953(A000583(n)). - _Michel Marcus_, Feb 23 2015
%e A055565 a(2) = 7 because 2^4 = 16 and 1+6 = 7.
%p A055565 for i from 0 to 200 do printf(`%d,`,add(j, j=convert(i^4, base, 10))) od;
%t A055565 a[n_Integer]:=Apply[Plus, IntegerDigits[n^4]]; Table[a[n], {n, 0, 100}] (* _Vincenzo Librandi_, Feb 23 2015 *)
%o A055565 (Sage) [sum((n^4).digits()) for n in (0..70)] # _Bruno Berselli_, Feb 23 2015
%o A055565 (PARI) a(n) = sumdigits(n^4); \\ _Seiichi Manyama_, Nov 16 2021
%Y A055565 Cf. A000583, A007953, A055570, A055575 (fixed points), A373914.
%Y A055565 Other powers: A004159, A004164, A055566, A055567, A066588.
%K A055565 nonn,easy,base
%O A055565 0,3
%A A055565 _Henry Bottomley_, Jun 19 2000
%E A055565 More terms from _James Sellers_, Jul 04 2000