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URL: https://oeis.org/A262285

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A262285
Primes whose binary expansion begins 111.
8
7, 29, 31, 59, 61, 113, 127, 227, 229, 233, 239, 241, 251, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997, 1009, 1013, 1019, 1021, 1801, 1811, 1823, 1831, 1847, 1861, 1867, 1871, 1873
OFFSET
1,1
LINKS
MAPLE
lis:=[]; q:=7;
for i from 1 to 10 do for j from 1 to 2^i-1 do
if isprime(q*2^i+j) then lis:=[op(lis), q*2^i+j]; fi; od: od:
lis;
MATHEMATICA
Select[FromDigits[#, 2]&/@(Join[{1, 1, 1}, #]&/@Flatten[Table[Tuples[{0, 1}, n], {n, 0, 8}], 1]), PrimeQ] (* or *) Select[Prime[Range[ 3, 350]], Take[ IntegerDigits[ #, 2], 3]=={1, 1, 1}&] (* Harvey P. Dale, May 02 2021 *)
CROSSREFS
Primes whose binary expansion begins with binary expansion of 1, 2, 3, 4, 5, 6, 7: A000040, A080165, A080166, A262286, A262284, A262287, A262285.
Suggested by A262350.
Column k=7 of A262365.
Sequence in context: A181942 A140447 A038934 * A383215 A041088 A107923
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Sep 19 2015
STATUS
approved