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A374178
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a(n) is the least prime p such that p and the next prime > p have exactly n common 1's in their binary expansion.
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0
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2, 5, 19, 29, 181, 359, 379, 983, 3821, 3581, 8179, 16111, 81901, 98297, 131059, 131063, 524269, 917471, 3145679, 4128763, 16744423, 16776187, 58720223, 117440381, 266330047, 468713467, 536870879, 1073741309, 2147483629, 4294967231, 8589410287, 33285865469
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OFFSET
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1,1
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COMMENTS
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1
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LINKS
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EXAMPLE
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a(n): 2 5 19 29 181
np 3 7 23 31 191
[1 0] [1 0 1] [1 0 0 1 1] [1 1 1 0 1] [1 0 1 1 0 1 0 1]
[1 1] [1 1 1] [1 0 1 1 1] [1 1 1 1 1] [1 0 1 1 1 1 1 1]
^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^
n: 1 2 3 4 5
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PROG
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(Python)
from sympy import nextprime
p = 2
while (q:=nextprime(p)):
if (p&q).bit_count() == n:
return p
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CROSSREFS
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KEYWORD
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nonn,base,new
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AUTHOR
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STATUS
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approved
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