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 A245337 #20 Jul 31 2025 03:48:47 %S A245337 0,1,2,3,4,5,6,6,7,8,9,10,11,12,11,12,13,14,15,16,17,15,16,17,18,19, %T A245337 20,21,18,19,20,21,22,23,24,20,21,22,23,24,25,26,21,22,23,24,25,26,27, %U A245337 21,22,23,24,25,26,27,27,28,29,30,31,32,33,26,27,28,29,30 %N A245337 Sum of digits of n in fractional base 7/6. %C A245337 The base 7/6 expansion is unique and thus the sum of digits function is well-defined. %H A245337 Amiram Eldar, <a href="/A245337/b245337.txt">Table of n, a(n) for n = 0..10000</a> %H A245337 <a href="/index/Ba#base_fractional">Index entries for sequences related to fractional bases</a>. %F A245337 a(n) = A007953(A024643(n)). - _Amiram Eldar_, Jul 31 2025 %e A245337 In base 7/6 the number 7 is represented by 60 and so a(7) = 6+0 = 6. %t A245337 a[n_] := a[n] = If[n == 0, 0, a[6 * Floor[n/7]] + Mod[n, 7]]; Array[a, 100, 0] (* _Amiram Eldar_, Jul 31 2025 *) %o A245337 (Sage) # uses [basepqsum from A245355] %o A245337 [basepqsum(7,6,y) for y in [0..200]] %o A245337 (PARI) a(n) = if(n == 0, 0, a(n\7 * 6) + n % 7); \\ _Amiram Eldar_, Jul 31 2025 %Y A245337 Cf. A024643, A007953, A053828. %K A245337 nonn,base,easy %O A245337 0,3 %A A245337 _James Van Alstine_, Jul 18 2014