

A091932


Primes that remain prime when their leading digit in binary representation is replaced by 0.


8



7, 11, 13, 19, 23, 29, 37, 43, 61, 67, 71, 83, 101, 107, 131, 139, 151, 157, 181, 199, 211, 229, 241, 263, 269, 293, 317, 353, 359, 383, 419, 449, 467, 479, 523, 541, 571, 601, 613, 619, 643, 661, 691, 709, 739, 751, 769, 823, 829, 859, 991, 1021, 1031
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OFFSET

1,1


COMMENTS

A053645(a(n)) is prime.
Primes p such that p  2^floor(log2(p)) is prime  T. D. Noe, Apr 08 2011


LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000


FORMULA

A118953(A049084(a(n))) = 1; subsequence of A065380.  Reinhard Zumkeller, May 07 2006


EXAMPLE

A000040(12)=37 > '100101' > '[1]00101' > '[0]00101' > '101' > 5, therefore 37 is a term.


MATHEMATICA

Select[Prime[Range[100]], PrimeQ[#  2^Floor[Log[2, #]]] &] (* T. D. Noe, Apr 08 2011 *)
Select[Prime[Range[200]], PrimeQ[FromDigits[Rest[ IntegerDigits[ #, 2]], 2]]&] (* Harvey P. Dale, Apr 08 2016 *)


CROSSREFS

Cf. A091931.
Cf. A118958.
Sequence in context: A152469 A115558 A067466 * A165349 A160024 A063911
Adjacent sequences: A091929 A091930 A091931 * A091933 A091934 A091935


KEYWORD

nonn


AUTHOR

Reinhard Zumkeller, Feb 14 2004


STATUS

approved



