login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


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: A174330 A099329 A182871 * A053440 A329724 A143332

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 6 02:20 EDT 2020. Contains 333267 sequences. (Running on oeis4.)