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A161601 Positive integers k that are less than the value of the reversal of k's representation in binary. 3
11, 19, 23, 35, 37, 39, 43, 47, 55, 67, 69, 71, 75, 77, 79, 83, 87, 91, 95, 103, 111, 131, 133, 135, 137, 139, 141, 143, 147, 149, 151, 155, 157, 159, 163, 167, 171, 173, 175, 179, 183, 187, 191, 199, 203, 207, 215, 223, 239, 259, 261, 263, 265, 267, 269, 271 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

By "reversal" of k's representation in binary, it is meant: write k in binary, reverse the order of its digits, and read the result as a binary value.

This sequence contains only odd integers.

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

37 = 100101_2; its digital reversal is 101001_2 = 41. Since 37 < 41, 37 is in this sequence.

MAPLE

a := proc (n) local n2, sz, rv: n2 := convert(n, base, 2): sz := nops(n2): rv := add(n2[j]*2^(sz-j), j = 1 .. sz): if n < rv then n else end if end proc; seq(a(n), n = 1 .. 280); # Emeric Deutsch, Jun 28 2009

MATHEMATICA

Select[Range[300], FromDigits[Reverse[IntegerDigits[#, 2]], 2]>#&] (* Harvey P. Dale, Mar 19 2016 *)

CROSSREFS

Cf. A030101, A006995, A161602, A161603.

Sequence in context: A165947 A129517 A287061 * A031406 A280993 A105908

Adjacent sequences:  A161598 A161599 A161600 * A161602 A161603 A161604

KEYWORD

base,nonn

AUTHOR

Leroy Quet, Jun 14 2009

EXTENSIONS

Extended by Emeric Deutsch, Jun 28 2009

Edited by Jon E. Schoenfield, Feb 24 2019

STATUS

approved

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Last modified March 26 07:03 EDT 2019. Contains 321481 sequences. (Running on oeis4.)