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 A362471 #49 Apr 30 2023 02:01:21 %S A362471 1,2,3,4,5,5,6,5,4,3,2,3,4,5,6,7,7,6,6,5,5,4,5,5,6,6,7,7,7,6,7,6,5,6, %T A362471 7,6,6,7,7,7,8,7,7,6,7,7,8,7,8,7,8,8,8,7,6,6,7,8,8,7,7,8,8,8,8,7,8,8, %U A362471 8,9,9,8,9,8,9,9,8,8,9,8,8,9,10,9,9,9,8,7,7 %N A362471 a(n) is the smallest number of 1's used in expressing n as a calculation containing only decimal repunits and operators +, -, * and /. %C A362471 Here, fractions are not allowed as intermediate results. %C A362471 See A362626 for the variant that allows such fractions. The sequences differ first at a(74) and its immediate neighbors, since a(74) = 8 > 7 = A362626(74). See the example in A362626. - _Peter Munn_, Apr 28 2023 %H A362471 Michael S. Branicky, <a href="/A362471/b362471.txt">Table of n, a(n) for n = 1..10000</a> %F A362471 a(n+1) <= a(n) + 1. %F A362471 a(n) <= a(i) + a(j), for all i O j = n, for O = +, -, *, /. %e A362471 For n = 6, 6 = (1+1)*(1+1+1), so a(6) = 5. %e A362471 For n = 32, 32 = 11*(1+1+1)-1, so a(32) = 6. %e A362471 For n = 37, 37 = 111/(1+1+1), so a(37) = 6. %e A362471 For n = 78, 78 = 111-(11)*(1+1+1), so a(78) = 8. %Y A362471 Cf. A002275, A005245, A091333, A133344, A362626. %K A362471 nonn,base %O A362471 1,2 %A A362471 _Yifan Xie_, _Haochen Mi_ and _Michael S. Branicky_, Apr 21 2023