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A115778 Consider the Levenshtein distance between k considered as a decimal string and k considered as a binary string. Then a(n) is the least number m such that the Levenshtein distance is n or 0 if no such number exists.

%I A115778 #14 Jul 16 2015 05:11:32
%S A115778 1,0,2,4,8,22,32,64,222,256,512,2044,2222,4222,8192,22222,32768,65536,
%T A115778 222222,262144,524288,2097152,2222222,4194322,8388622,22222222,
%U A115778 33554432,67222222,222222222,268435456,536872222,2147483650,2147483648,4294967296,8589934592,22222222222
%N A115778 Consider the Levenshtein distance between k considered as a decimal string and k considered as a binary string. Then a(n) is the least number m such that the Levenshtein distance is n or 0 if no such number exists.
%C A115778 Difference between A115779 and A115778: 1, 0, 9, 11, 103, 99, 979, 1047, 1789, 10855, 15599, 109067, 128789, 1006889, 1102919, 1988889, 11078343, ...,.
%F A115778 a(1)=0 since no number satisfies the definition and generally a(n)>= 2^(n+1).
%p A115778 f:= n -> StringTools:-Levenshtein(convert(n,string), convert(convert(n,binary),string)):
%p A115778 A:= Vector(20):
%p A115778 for n from 3 to 10^6 do
%p A115778   v:= f(n);
%p A115778   if A[v] = 0 then A[v]:= n fi
%p A115778 od:
%p A115778 1,0,seq(A[n],n=2..20); # _Robert Israel_, Jul 16 2015
%t A115778 levenshtein[s_List, t_List] := Module[{d, n = Length@s, m = Length@t}, Which[s === t, 0, n == 0, m, m == 0, n, s != t, d = Table[0, {m + 1}, {n + 1}]; d[[1, Range[n + 1]]] = Range[0, n]; d[[Range[m + 1], 1]] = Range[0, m]; Do[d[[j + 1, i + 1]] = Min[d[[j, i + 1]] + 1, d[[j + 1, i]] + 1, d[[j, i]] + If[s[[i]] === t[[j]], 0, 1]], {j, m}, {i, n}]; d[[ -1, -1]]]];
%t A115778 t = Table[0, {25}]; f[n_] := levenshtein[ IntegerDigits[n], IntegerDigits[n, 2]]; Do[a = f[n]; If[ t[[a+1]] == 0, t[[a+1]] = n; Print[{a, n}]], {n, 10^6}]; t
%Y A115778 Cf. A000027, A007088, A115777.
%K A115778 nonn,base
%O A115778 0,3
%A A115778 _Robert G. Wilson v_, Jan 26 2006
%E A115778 a(26)-a(35) from _Lars Blomberg_, Jul 16 2015