A143245 Primes in A098957.

3, 5, 7, 13, 11, 17, 29, 23, 31, 41, 37, 53, 61, 43, 47, 97, 113, 73, 101, 67, 83, 107, 71, 127, 193, 233, 197, 229, 181, 173, 131, 163, 227, 251, 199, 167, 151, 223, 257, 449, 353, 337, 433, 409, 313, 421, 277, 373, 269, 461, 349, 509, 307, 331, 491, 283, 443

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Gray Code

Maple

brev:= proc(n) local L;
  L:= convert(n, base, 2);
  add(L[-i]*2^(i-1), i=1..nops(L))
end proc:
select(isprime, [seq(brev(ithprime(i)), i=1..100)]); # Robert Israel, Apr 03 2019

Mathematica

GrayCodeList[k_] := Module[{b = IntegerDigits[k, 2], i}, Do[ If[b[[i - 1]] == 1, b[[i]] = 1 - b[[i]]], {i, Length[b], 2, -1} ]; b ]; a[n_] = GrayCodeList[Prime[n]]; a0 = Table[Sum[a[n][[m + 1]]*2^m, {m, 0, Length[a[n]] - 1}], {n, 1, 200}]; Flatten[Table[If[PrimeQ[a0[[n]]], a0[[n]], {}], {n, 1, 200}]]

Prog

(PARI) forprime(p=2, 1e3, v=binary(p); s=0; forstep(i=#v, 1, -1, s+=s+v[i]); if(isprime(s), print1(s", "))) \\ Charles R Greathouse IV, Nov 07 2011

Crossrefs

Cf. A098957.

Sequence in context: A161329 A111745 A098957 * A018205 A370762 A121047

Adjacent sequences: A143242 A143243 A143244 * A143246 A143247 A143248

Keyword

nonn,look,base

Author

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

Status

approved