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A140900 A nonnegative integer n is included if the binary representation of n and the digit-reversal (with leading 0's) of the binary representation of n do not have any 1's in the same position. 5
0, 2, 4, 8, 10, 12, 16, 18, 24, 32, 34, 36, 38, 40, 42, 48, 52, 56, 64, 66, 68, 70, 80, 82, 96, 100, 112, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 160, 162, 168, 170, 176, 178, 192, 196, 200, 204, 208, 212, 224, 232, 240, 256, 258, 260, 262, 264 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
All terms of this sequence are even.
Number of terms less than or equal to 10^n: 1, 5, 26, 162, 1045, 5976, 38980, 249229, 1416583, 9381238, ..., . - Robert G. Wilson v, Aug 04 2008
Number of terms < 2^k: 1, 2, 3, 6, 18, 27, 54, 81,... (A038754). - T. D. Noe, Apr 09 2009
LINKS
EXAMPLE
36 in binary is 100100. The digit-reversal (with leading 0's) of this is 001001. These binary representations have no 1's in the same location (i.e., they can be added in binary without any carries). So 36 is in this sequence.
MATHEMATICA
fQ[n_] := Block[{id = IntegerDigits[n, 2]}, Max@ Union[id + Reverse@ id] < 2]; Select[2 Range[0, 134], fQ@# &] (* Robert G. Wilson v, Aug 04 2008 *)
PROG
(PARI) is(n) = my (b=if (n, binary(n), [0])); vecmax(b+Vecrev(b))<=1 \\ Rémy Sigrist, Jun 11 2022
CROSSREFS
A035928 is a subsequence.
Sequence in context: A346502 A321580 A224694 * A166936 A166245 A276623
KEYWORD
base,nonn
AUTHOR
Leroy Quet, Jul 24 2008
EXTENSIONS
More terms from Robert G. Wilson v, Aug 04 2008
STATUS
approved

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Last modified July 18 16:16 EDT 2024. Contains 374388 sequences. (Running on oeis4.)