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A199328
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Palindromic primes in the sense of A007500 with digits '0', '1' and '8' only.
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2
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11, 101, 181, 1181, 1811, 18181, 108881, 110881, 118081, 180181, 180811, 181081, 188011, 188801, 1008001, 1088081, 1110881, 1180811, 1181881, 1808801, 1880111, 1880881, 1881811, 1881881, 10001081, 10001801, 10011101, 10080011, 10101181, 10111001, 10111081, 10180801, 10188811, 10808101, 10810001
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OFFSET
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1,1
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COMMENTS
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LINKS
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PROG
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(PARI) a(n=50, L=[0, 1, 8], show=0)={my(t); for(d=1, 1e9, u=vector(d, i, 10^(d-i))~; forvec(v=vector(d, i, [1+(i==1&!L[1]), #L]), isprime(t=vector(d, i, L[v[i]])*u)|next; isprime(A004086(t))|next; show&print1(t", "); n--|return(t)))}
(Python)
from itertools import product
from sympy import isprime
A199328_list = [n for n in (int(''.join(s)) for s in product('018', repeat=10)) if isprime(n) and isprime(int(str(n)[::-1]))] # Chai Wah Wu, Dec 17 2015
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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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