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Numbers k such that k, k+1 and k+2 have the same period of binary representation (A007733).
1

%I #5 Apr 03 2020 21:04:08

%S 23284,77906,509737,717817,996601,1132177,1550377,3264241,3896546,

%T 4326962,4491362,4542457,5978857,7097161,8981977,9628921,10140386,

%U 11098201,11472337,12078217,12699122,13335457,14079577,16795417,17796146,17807017,18832082,20221106,21096146

%N Numbers k such that k, k+1 and k+2 have the same period of binary representation (A007733).

%C Numbers k such that A007733(k) = A007733(k+1) = A007733(k+2).

%e 23284 is a term since A007733(23284) = A007733(23285) = A007733(23286) = 388.

%t f[n_] := MultiplicativeOrder[2, n/(2^IntegerExponent[n, 2])]; f1 = f[1]; f2 = f[2]; seq = {}; Do[f3 = f[n]; If[f1 == f2 && f2 == f3, AppendTo[seq, n-2]]; f1 = f2; f2 = f3, {n, 3, 10^6}]; seq

%Y Cf. A007733, A333745.

%K nonn

%O 1,1

%A _Amiram Eldar_, Apr 03 2020