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 A038488 #14 Apr 05 2025 15:13:20
%S A038488 91,739,811,819,6571,6643,6651,7291,7299,7371,59059,59131,59139,59779,
%T A038488 59787,59859,65611,65619,65691,66339,531451,531523,531531,532171,
%U A038488 532179,532251,538003,538011,538083,538731,590491,590499,590571,591219,597051,4782979,4783051
%N A038488 Sums of 3 distinct powers of 9.
%H A038488 Amiram Eldar, <a href="/A038488/b038488.txt">Table of n, a(n) for n = 1..10000</a>
%t A038488 Sort[Plus @@@ Subsets[9^Range[0, 6], {3}]] (* _Amiram Eldar_, Jul 14 2022 *)
%o A038488 (Python)
%o A038488 from math import isqrt, comb
%o A038488 from sympy import integer_nthroot
%o A038488 def A038488(n): return 9**((r:=n-1-comb((m:=integer_nthroot(6*n,3)[0])+(t:=(n>comb(m+2,3)))+1,3))-comb((k:=isqrt(b:=r+1<<1))+(b>k*(k+1)),2))+9**((a:=isqrt(s:=n-comb(m-(t^1)+2,3)<<1))+((s<<2)>(a<<2)*(a+1)+1))+9**(m+t+1) # _Chai Wah Wu_, Apr 05 2025
%Y A038488 Base-9 interpretation of A038445.
%Y A038488 Cf. A001019, A038487, A038489.
%K A038488 nonn,easy
%O A038488 1,1
%A A038488 _Olivier Gérard_
%E A038488 Offset corrected by _Amiram Eldar_, Jul 14 2022