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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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified May 25 05:56 EDT 2017. Contains 287012 sequences.