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 A038487 #34 Apr 05 2025 15:02:41
%S A038487 10,82,90,730,738,810,6562,6570,6642,7290,59050,59058,59130,59778,
%T A038487 65610,531442,531450,531522,532170,538002,590490,4782970,4782978,
%U A038487 4783050,4783698,4789530,4842018,5314410,43046722,43046730,43046802,43047450,43053282
%N A038487 Sums of two distinct powers of 9.
%H A038487 Robert Israel, <a href="/A038487/b038487.txt">Table of n, a(n) for n = 1..10001</a>
%F A038487 a(n)=9^A002024(n)+9^A002262(n). - _M. F. Hasler_, Aug 31 2014
%p A038487 N:= 10^10: # to get all terms <= N
%p A038487 {seq(seq(9^a+9^b,b=0..a-1),a=1..floor(log[9](N)))}; # _Robert Israel_, Aug 31 2014
%t A038487 Total/@Subsets[9^Range[0,10],{2}]//Union (* _Harvey P. Dale_, Aug 25 2023 *)
%o A038487 (PARI) for(a=0,19,for(b=0,a-1,print1(9^a+9^b,","))) \\ _M. F. Hasler_, Aug 31 2014
%o A038487 (Python)
%o A038487 from math import isqrt
%o A038487 def A038487(n): return 9**(m:=isqrt(n<<3)+1>>1)+9**(n-1-(m*(m-1)>>1)) # _Chai Wah Wu_, Apr 05 2025
%Y A038487 Base 9 interpretation of A038444.
%K A038487 nonn,easy
%O A038487 1,1
%A A038487 _Olivier Gérard_
%E A038487 More terms from _Vincenzo Librandi_, Aug 06 2009
%E A038487 Corrected by _Harvey P. Dale_, Aug 31 2014
%E A038487 Offset changed from 0 to 1 by _M. F. Hasler_, Aug 31 2014