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A204219 Primes whose binary reversal is not prime. 4
2, 19, 59, 79, 89, 103, 109, 137, 139, 149, 157, 179, 191, 211, 239, 241, 271, 281, 293, 311, 317, 347, 367, 379, 389, 397, 401, 419, 439, 457, 467, 499, 523, 541, 547, 557, 563, 569, 587, 593, 607, 613, 641, 647, 659, 673, 719, 733, 743, 751, 761, 769, 787, 809, 811, 829, 859, 863, 877, 887, 919, 929, 971, 977, 983, 991, 997 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Complement of A074832 in A000040.

LINKS

Table of n, a(n) for n=1..67.

MATHEMATICA

a = {}; For[n = 1, n <= 1000, n++, If[PrimeQ[n], {d = Reverse[ IntegerDigits[n, 2]]; If[!PrimeQ[FromDigits[d, 2]], AppendTo[a, n]]}]]; a (* Hasler *)

Select[Prime[Range[170]], Not[PrimeQ[FromDigits[Reverse[IntegerDigits[#, 2]], 2]]] &] (* Alonso del Arte, Jan 13 2012 *)

PROG

(PARI) forprime(p=1, 1e3, isprime(sum(i=1, #b=binary(p), b[i]<<i)\2))|print1(p", "))

CROSSREFS

Cf. A076056, the base 10 equivalent.

Sequence in context: A125201 A215392 A140544 * A042149 A218547 A232537

Adjacent sequences:  A204216 A204217 A204218 * A204220 A204221 A204222

KEYWORD

nonn,base

AUTHOR

M. F. Hasler, Jan 13 2012

STATUS

approved

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Last modified February 28 10:49 EST 2020. Contains 332323 sequences. (Running on oeis4.)