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 *)
PROG
(Python)
from itertools import count, islice
def A161601_gen(startvalue=1): # generator of terms >= startvalue
return filter(lambda n:n<int(bin(n)[-1:1:-1], 2), count(max(startvalue|1, 1), 2))
CROSSREFS
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