login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Numbers whose lengths of runs of 1's in their reversed binary expansion are weakly increasing.
1

%I #5 Nov 12 2019 19:23:14

%S 1,2,3,4,5,6,7,8,9,10,12,13,14,15,16,17,18,20,21,24,25,26,27,28,29,30,

%T 31,32,33,34,36,37,40,41,42,48,49,50,51,52,53,54,56,57,58,59,60,61,62,

%U 63,64,65,66,68,69,72,73,74,80,81,82,84,85,96,97,98,99

%N Numbers whose lengths of runs of 1's in their reversed binary expansion are weakly increasing.

%e The sequence of terms together with their reversed binary expansions begins:

%e 1: (1)

%e 2: (01)

%e 3: (11)

%e 4: (001)

%e 5: (101)

%e 6: (011)

%e 7: (111)

%e 8: (0001)

%e 9: (1001)

%e 10: (0101)

%e 12: (0011)

%e 13: (1011)

%e 14: (0111)

%e 15: (1111)

%e 16: (00001)

%e 17: (10001)

%e 18: (01001)

%e 20: (00101)

%e 21: (10101)

%e 24: (00011)

%t Select[Range[100],LessEqual@@Length/@Split[Join@@Position[Reverse[IntegerDigits[#,2]],1],#2==#1+1&]&]

%Y Complement of A328870.

%Y The version for prime indices is A304678.

%Y The binary expansion of n has A069010(n) runs of 1's.

%Y Cf. A000120, A003714, A014081, A112769, A164707, A245563, A328592.

%K nonn

%O 1,2

%A _Gus Wiseman_, Nov 12 2019