login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A157971 Odious twin locations: first members of pairs of consecutive odious numbers. 6
1, 7, 13, 21, 25, 31, 37, 41, 49, 55, 61, 69, 73, 81, 87, 93, 97, 103, 109, 117, 121, 127, 133, 137, 145, 151, 157, 161, 167, 173, 181, 185, 193, 199, 205, 213, 217, 223, 229, 233, 241, 247, 253, 261, 265, 273, 279, 285, 289, 295 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

An odious number (A000069) is a nonnegative integer with an odd number of ones in its binary expansion.

In the reference it is shown that these odious twins alternate with the evil twins (see A157970), which are pairs of consecutive odious numbers (A000069) having an odd number of ones in their binary expansions).

REFERENCES

Chris Bernhardt, "Evil Twins Alternate with Odious Twins", Math. Mag. 82 (2009) 57-62.

LINKS

Eric Weisstein's World of Mathematics, Odious Number

EXAMPLE

The sequence of odious numbers (A000069) begins 1,2,4,7,8,11,13,14,16,19,21,..., so the first few odious twins are at 1,7,13, ... .

CROSSREFS

A000069, A001969, A157970

Sequence in context: A126621 A109331 A054858 * A135275 A013652 A099988

Adjacent sequences:  A157968 A157969 A157970 * A157972 A157973 A157974

KEYWORD

nonn

AUTHOR

John W. Layman (layman(AT)math.vt.edu), Mar 10 2009

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 00:09 EST 2012. Contains 205978 sequences.