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 A038490 #24 Apr 04 2025 14:37:27
%S A038490 12,122,132,1332,1342,1452,14642,14652,14762,15972,161052,161062,
%T A038490 161172,162382,175692,1771562,1771572,1771682,1772892,1786202,1932612,
%U A038490 19487172,19487182,19487292,19488502,19501812,19648222,21258732,214358882,214358892,214359002,214360212,214373522,214519932,216130442
%N A038490 Sums of 2 distinct powers of 11.
%H A038490 Robert Israel, <a href="/A038490/b038490.txt">Table of n, a(n) for n = 1..10000</a>
%p A038490 seq(seq(11^i+11^j,i=0..j-1),j=1..10); # _Robert Israel_, Jun 21 2018
%t A038490 Take[Union[Plus@@@Subsets[11^Range[0,20],{2}]],50] (* _Harvey P. Dale_, Dec 16 2010 *)
%o A038490 (Python)
%o A038490 from math import isqrt
%o A038490 def A038490(n): return 11**(m:=isqrt(n<<3)+1>>1)+11**(n-1-(m*(m-1)>>1)) # _Chai Wah Wu_, Apr 04 2025
%Y A038490 Base 11 interpretation of A038444.
%K A038490 nonn,easy
%O A038490 1,1
%A A038490 _Olivier Gérard_
%E A038490 More terms from _Vincenzo Librandi_, Aug 06 2009
%E A038490 a(33)=214373522 inserted by _Robert Israel_, Jun 21 2018