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A236528
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Start with 4; thereafter, primes obtained by concatenating to the end of previous term the next smallest number that will produce a prime.
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0
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4, 41, 419, 41911, 4191119, 41911193, 419111933, 41911193341, 4191119334151, 419111933415151, 41911193341515187, 4191119334151518719, 419111933415151871963, 41911193341515187196323, 4191119334151518719632313, 419111933415151871963231329
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OFFSET
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1,1
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COMMENTS
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a(n+1) is the next smallest prime beginning with a(n). Initial term is 4.
After a(1), these are the primes arising in A069606.
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LINKS
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EXAMPLE
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a(1) = 4 by definition.
a(2) is the next smallest prime beginning with 4, so a(2) = 41.
a(3) is the next smallest prime beginning with 41, so a(3) = 419.
...and so on.
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PROG
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(Python)
import sympy
from sympy import isprime
def b(x):
..num = str(x)
..n = 1
..while n < 10**3:
....new_num = str(x) + str(n)
....if isprime(int(new_num)):
......print(int(new_num))
......x = new_num
......n = 1
....else:
......n += 1
b(4)
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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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