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 A344853 #37 Aug 08 2021 01:50:07 %S A344853 0,0,0,2,2,2,4,4,4,8,8,8,10,10,10,12,12,12,16,16,16,18,18,18,20,20,20, %T A344853 26,26,26,28,28,28,30,30,30,34,34,34,36,36,36,38,38,38,42,42,42,44,44, %U A344853 44,46,46,46,52,52,52,54,54,54,56,56,56,60,60,60,62,62,62 %N A344853 a(n) = n minus (sum of digits of n in base 3). %C A344853 All terms are even. %C A344853 In all sequences of the form f(n) = n minus (sum of digits of n in base b), every term appears b times consecutively. Here b = 3, hence terms are entries of A346502 repeated 3 times. - _Bernard Schott_, Jul 21 2021 %H A344853 Michael De Vlieger, <a href="/A344853/b344853.txt">Table of n, a(n) for n = 0..10000</a> %F A344853 a(n) = n - A053735(n). %F A344853 a(n) = 2 * A054861(n). %F A344853 a(n) = 2 * A004128(floor(n/3)). %F A344853 a(3*n) = a(3*n+1) = a(3*n+2). %e A344853 a(20) = 20 - (2 + 0 + 2) = 16 because 20 is written as 202 in base 3. %t A344853 a[n_] := n - Plus @@ IntegerDigits[n, 3]; Array[a, 70, 0] (* _Amiram Eldar_, May 30 2021 *) %o A344853 (PARI) a(n) = n - sumdigits(n, 3); \\ _Michel Marcus_, Jul 11 2021 %Y A344853 Cf. A011371 (in base 2), A066568 (in base 10). %Y A344853 Cf. A004128, A053735, A054861, A346502. %K A344853 base,easy,nonn %O A344853 0,4 %A A344853 _Thomas König_, May 30 2021