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A240167
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Lesser of the first cousin prime pair with n digits.
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2
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3, 13, 103, 1009, 10099, 100189, 1000033, 10000453, 100000123, 1000000093, 10000000597, 100000000069, 1000000000189, 10000000000279, 100000000001173, 1000000000000399, 10000000000001719, 100000000000002733, 1000000000000002493, 10000000000000000087
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OFFSET
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1,1
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COMMENTS
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Sum of reciprocals converges towards 0.421066...
It is only a (plausible) conjecture that this sequence is well-defined. See A152052. - N. J. A. Sloane, Aug 22 2014
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LINKS
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FORMULA
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PROG
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(Python)
import sympy
for i in range(100):
a=(10**i)
p=sympy.nextprime(a)
while not sympy.isprime(p+4):
p=sympy.nextprime(p)
print(p)
(PARI)
a(n)=my(p=nextprime(10^(n-1))); while(!isprime(p+4), p=nextprime(p+1)); return(p)
vector(50, n, a(n)) \\ Derek Orr, Aug 04 2014
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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