A161607 - OEIS

A161607

Positive integers k that are coprime to the value of the reversal of k's representation in binary.

1, 2, 4, 8, 11, 13, 16, 19, 22, 23, 25, 26, 29, 32, 37, 38, 41, 43, 44, 46, 47, 50, 52, 53, 55, 58, 59, 61, 64, 67, 71, 74, 76, 77, 79, 82, 83, 86, 88, 89, 91, 92, 94, 97, 100, 101, 103, 104, 106, 109, 110, 113, 115, 116, 118, 121, 122, 128, 131, 134, 137, 139, 142, 143

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OFFSET

1,2

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.

LINKS

Table of n, a(n) for n=1..64.

MAPLE

A030101 := proc(n) local bdgs; bdgs := convert(n, base, 2) ; add( op(-i, bdgs)*2^(i-1), i=1..nops(bdgs)) ; end: A161607 := proc(n) option remember ; local a; if n = 1 then 1; else for a from procname(n-1)+1 do if gcd(A030101(a), a) = 1 then RETURN(a) ; fi; od: fi; end: seq(A161607(n), n=1..100) ; # R. J. Mathar, Jul 04 2009

CROSSREFS

Cf. A030101.

Sequence in context: A243181 A236206 A078649 * A318206 A022442 A308163

Adjacent sequences: A161604 A161605 A161606 * A161608 A161609 A161610

KEYWORD

base,nonn

AUTHOR

Leroy Quet, Jun 14 2009

EXTENSIONS

More terms from R. J. Mathar, Jul 04 2009

STATUS

approved