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A138103 Numbers with an odd number of 1's in base 6 expansion. 1
1, 6, 8, 9, 10, 11, 13, 19, 25, 31, 36, 38, 39, 40, 41, 43, 48, 50, 51, 52, 53, 54, 56, 57, 58, 59, 60, 62, 63, 64, 65, 66, 68, 69, 70, 71, 73, 78, 80, 81, 82, 83, 85, 91, 97, 103, 109, 114, 116, 117, 118, 119, 121, 127, 133, 139, 145, 150, 152, 153, 154, 155, 157, 163 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

This is to A007092 (numbers in base 6) as A000069 (odious numbers: odd number of 1's in binary expansion) is to A007088 (numbers written in base 2) and as A137469 is to A007091 (numbers in base 5). Note that odd number of 1's in base 3 expansion is simply the odd numbers. This sequence includes, as a subset, A043373 = numbers n such that number of 1's in base 6 is 1.

This is strictly different from A043373.

Terms in this sequence but not in A043374 are 43, 223, 253, 258, 260, 261, 262, 263, 265, 271, 277, 283, 295,... - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 13 2008

EXAMPLE

a(1) = 1 because 1 base 10 = 1 base 6, which has an odd number (1) of ones.

a(2) = 6 because 6 base 10 = 10 base 6, which has an odd number (1) of ones.

a(3) = 8 because 8 base 10 = 12 base 6, which has an odd number (1) of ones.

a(11) = 36 because 36 base 10 = 100 base 6, which has an odd number (1) of ones.

a(17) = 43 because 43 base 10 = 111 base 6, which has an odd number (3) of ones.

MAPLE

isA138103 := proc(n) local a; a := 0 ; for d in convert(n, base, 6) do if d = 1 then a := a+1 ; fi ; od: RETURN( a mod 2 = 1) ; end: for n from 1 to 300 do if isA138103(n) then printf("%d, ", n) ; fi ; od: - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 13 2008

CROSSREFS

Cf. A000069, A007088, A007092, A043373, A137469.

Sequence in context: A043610 A043695 A076517 * A043373 A054047 A056653

Adjacent sequences:  A138100 A138101 A138102 * A138104 A138105 A138106

KEYWORD

base,easy,nonn,less

AUTHOR

Jonathan Vos Post (jvospost3(AT)gmail.com), May 03 2008

EXTENSIONS

Corrected and extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 13 2008

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Last modified February 16 16:00 EST 2012. Contains 205938 sequences.