cp's OEIS Frontend

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.

A135111 Numbers such that the digital sum base 2 and the digital sum base 3 are in a ratio of 2:3.

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%I A135111 #11 Sep 26 2016 21:31:55
%S A135111 5,33,78,106,116,142,150,154,156,170,178,184,202,204,210,215,226,228,
%T A135111 278,284,294,308,312,332,338,340,344,356,377,390,396,418,420,424,450,
%U A135111 455,467,473,483,513,526,534,550,582,586,588,596,600,612,619,624,629
%N A135111 Numbers such that the digital sum base 2 and the digital sum base 3 are in a ratio of 2:3.
%H A135111 G. C. Greubel, <a href="/A135111/b135111.txt">Table of n, a(n) for n = 1..1000</a>
%e A135111 a(1)=5, since ds_2(5):ds_3(5)=2:3.
%p A135111 select(t -> convert(convert(t,base,3),`+`)/convert(convert(t,base,2),`+`) = 3/2, [$1..1000]); # _Robert Israel_, Sep 26 2016
%t A135111 Select[Range[500], 3*Total[IntegerDigits[#, 2]] == 2*Total[IntegerDigits[#, 3]] &] (* _G. C. Greubel_, Sep 26 2016 *)
%o A135111 (PARI) isok(n) = 2*vecsum(digits(n, 3)) == 3*vecsum(digits(n, 2)); \\ _Michel Marcus_, Sep 26 2016
%Y A135111 Cf. A007953, A054899, A131451, A133620, A133900, A134599.
%K A135111 nonn,base
%O A135111 1,1
%A A135111 _Hieronymus Fischer_, Dec 24 2007