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A286333
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Primes p where all the cyclic shifts of their digits to the left also produce primes except the last one before reaching p again.
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2
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19, 23, 29, 41, 43, 47, 53, 59, 61, 67, 83, 89, 101, 103, 107, 127, 149, 157, 163, 181, 191, 307, 317, 331, 359, 367, 701, 709, 727, 739, 757, 761, 787, 797, 907, 937, 941, 947, 983, 1103, 1109, 1123, 1181, 1301, 1319, 1327, 1949, 1951, 1979, 1987, 1993, 3121, 3187, 3361, 3373, 3701
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OFFSET
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1,1
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COMMENTS
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a(144) = 733793111393, a(145) is larger than 10^16 (if it exists).
Can be considered as primitive terms of A270083, i.e. terms in A270083 can be obtained by cyclic shifts of the digits of terms in this sequence (and leading zeros are not allowed). - Chai Wah Wu, May 21 2017
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LINKS
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EXAMPLE
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1123 is a member as all the cyclic shifts of its digits to the left result are primes (1231, 2311) except the last one (3112) before reaching the original prime.
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MATHEMATICA
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cyclDigs[k_]:= FromDigits/@ NestList[RotateLeft, IntegerDigits[k], IntegerLength[k]-1]; lftSftNearCircPrmsInBtw[m_, n_]:= ParallelMap[If[ AllTrue[Most[cyclDigs[#]], PrimeQ] && Not@ PrimeQ[Last[cyclDigs[#]]], #, Nothing] &, Prime @ Range[PrimePi[m], PrimePi[n]]];
lftSftNearCircPrmsInBtw[19, 10^7]
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PROG
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(Python)
from itertools import product
from sympy import isprime
for l in range(14):
for w in product('1379', repeat=l):
for d in '0123456789':
for t in '1379':
s = ''.join(w)+d+t
n = int(s)
for i in range(l+1):
if not isprime(int(s)):
break
s = s[1:]+s[0]
else:
if n > 10 and not isprime(int(s)):
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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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