A292204 Primes as they appear in A006068.

3, 2, 7, 5, 13, 11, 31, 29, 17, 19, 23, 61, 59, 53, 37, 47, 41, 43, 127, 113, 97, 103, 101, 109, 107, 67, 71, 79, 73, 89, 83, 251, 241, 227, 229, 239, 233, 193, 199, 197, 223, 211, 131, 137, 139, 157, 151, 149, 191, 179, 181, 163, 167, 173, 509, 499, 503, 487, 491, 449, 463, 461

Offset

1,1

Comments

a(n) is the i-th prime (as it appears in A000040) for i = 2, 1, 4, 3, 6, 5, 9, 10, 11, 8, 7, 15, 17, 18, 16, 14, etc.

Links

Table of n, a(n) for n=1..62.

Mathematica

f[n_] := BitXor @@ Table[ Floor[n/2^m], {m, 0, Floor[Log2@ n]}]; Select[ Array[f, 300], PrimeQ]

Prog

(PARI) grayinto(n) = my(B=n); for(k=1, log(n+1)\log(2), B=bitxor(B, n\2^k)); B;
lista(nn) = for (n=1, nn, if (isprime(p=grayinto(n)), print1(p, ", "))); \\ Michel Marcus, Oct 10 2017
(Python)
from itertools import count, islice
from sympy import isprime
def A292204_gen(): # generator of terms
    for n in count(0):
        k, m = n, n>>1
        while m > 0:
            k ^= m
            m >>= 1
        if isprime(k):
            yield k
A292204_list = list(islice(A292204_gen(), 30)) # Chai Wah Wu, Jun 29 2022

Crossrefs

Cf. A006068, A292203, A292205.

Sequence in context: A215622 A195820 A006921 * A292203 A295642 A014693

Adjacent sequences: A292201 A292202 A292203 * A292205 A292206 A292207

Keyword

nonn

Author

Robert G. Wilson v, Sep 11 2017

Status

approved