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 A230856 #11 Nov 01 2013 14:12:36 %S A230856 248,492,978,1222,1708,1952,2192,2196,2436,2680,3166,3410,3896,4140, %T A230856 4380,4384,4624,4868,5354,5598,6084,6328,6566,6572,6810,7054,7540, %U A230856 7784,8270,8514,8754,8758,8998,9242,9728,9972,10458,10702,10942,10946,11186,11430,11916,12160,12646,12890,13128 %N A230856 Numbers n such that m + (sum of digits in base-3 representation of m) = n has exactly four solutions. %H A230856 Donovan Johnson, <a href="/A230856/b230856.txt">Table of n, a(n) for n = 1..10000</a> %H A230856 <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a> %Y A230856 Related base-3 sequences: A053735, A134451, A230641, A230642, A230643, A230853, A230854, A230855, A230856, A230639, A230640, A010063 (trajectory of 1) %K A230856 nonn,base %O A230856 1,1 %A A230856 _N. J. A. Sloane_, Oct 31 2013