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

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A143329 Primes in A143292. 1
3, 2, 7, 11, 19, 61, 47, 109, 73, 223, 211, 251, 239, 167, 151, 157, 137, 439, 421, 419, 499, 463, 331, 787, 827, 971, 991, 1009, 947, 911, 641, 647, 659, 701, 757, 613, 569, 521, 1549, 1663, 1747, 1789, 1697, 1667, 1933, 1951, 1877, 1291, 1367, 1531, 1447, 1451 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Primes that are Gray codes of other "source" primes, ordered along increasing source primes, i.e., in the order of appearance in A143292.

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Kevin Ryde, A143329 gray code primes sample values, SeqFan Mailing list Apr 19 2012

MATHEMATICA

GrayCode[n_] := BitXor[n, Floor[n/2]]; Select[ GrayCode@ Prime@ Range@ 275, PrimeQ] (* Robert G. Wilson v, Mar 11 2015 *)

PROG

(MAGMA)

I2B:=func<i | [b eq 1: b in IntegerToSequence(i, 2)]>;

B2I:=func<s | SequenceToInteger([b select 1 else 0: b in s], 2)>;

[g: n in [1..999] | IsPrime(g) where g is B2I(Xor(I2B(i), I2B(i div 2)cat[false])) where i is NthPrime(n)]; // Jason Kimberley, Apr 19 2012

(PARI) forprime(p=2, 3e6, if(isprime(t=bitxor(p, p>>1)), print1(t", "))) \\ Charles R Greathouse IV, Apr 19 2012

CROSSREFS

Sequence in context: A099329 A182871 A219187 * A053440 A143332 A255919

Adjacent sequences:  A143326 A143327 A143328 * A143330 A143331 A143332

KEYWORD

nonn,easy

AUTHOR

Roger L. Bagula and Gary W. Adamson, Oct 21 2008

EXTENSIONS

Jason Kimberley corrected all terms after a(38) at the suggestion of Kevin Ryde, Apr 19 2012

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy .

Last modified November 21 07:11 EST 2017. Contains 294996 sequences.