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 A230631 #23 Oct 30 2024 21:10:44
%S A230631 0,2,4,6,5,7,9,11,10,12,14,16,15,17,19,21,17,19,21,23,22,24,26,28,27,
%T A230631 29,31,33,32,34,36,38,34,36,38,40,39,41,43,45,44,46,48,50,49,51,53,55,
%U A230631 51,53,55,57,56,58,60,62,61,63,65,67,66,68,70,72,65,67,69,71,70,72,74,76,75,77,79,81,80,82,84,86,82
%N A230631 a(n) = n + (sum of digits in base-4 representation of n).
%H A230631 Donovan Johnson, <a href="/A230631/b230631.txt">Table of n, a(n) for n = 0..10000</a>
%H A230631 <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a>
%F A230631 a(n) = A053737(n) + n. - _Reinhard Zumkeller_, Mar 20 2015
%o A230631 (Haskell) a230631 n = a053737 n + n -- _Reinhard Zumkeller_, Mar 20 2015
%o A230631 (PARI) apply( {A230631(n)=n+sumdigits(n,4)}, [0..99]) \\ _M. F. Hasler_, Oct 30 2024
%Y A230631 Cf. A010064 (missing numbers), A230632 (number of inverses), A230633-A230635.
%Y A230631 Related base-4 sequences: A053737, A230632, A010064, A230633, A230634, A230635, A230636, A230637, A230638, A010065 (trajectory of 1)
%K A230631 nonn,base
%O A230631 0,2
%A A230631 _N. J. A. Sloane_, Oct 30 2013