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 A135123 #6 Sep 26 2016 21:32:06 %S A135123 1,12,13,114,115,366,367,477,687,864,865,876,877,1086,1087,1305,1326, %T A135123 1327,1386,1387,1596,1597,1626,1627,1656,1657,1746,1747,1836,1837, %U A135123 1956,1957,2595,2607,2646,2647,3276,3277,3906,3907,3948,3949,4068,4069,5438 %N A135123 Numbers such that the digital sum base 2 and the digital sum base 3 and the digital sum base 6 all are equal. %H A135123 G. C. Greubel, <a href="/A135123/b135123.txt">Table of n, a(n) for n = 1..1200</a> %e A135123 a(2)=12, since ds_2(12)=ds_3(12)=ds_6(12), where ds_x=digital sum base x. %t A135123 Select[Range[5000], Total[IntegerDigits[#, 2]] == Total[IntegerDigits[#, 3]] == Total[IntegerDigits[#, 6]] &] (* _G. C. Greubel_, Sep 26 2016 *) %Y A135123 Cf. A007953, A054899, A131451, A133620, A133900, A134599, A135100, A135110, A135120, A037308. %K A135123 nonn,base %O A135123 1,2 %A A135123 _Hieronymus Fischer_, Dec 31 2007