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 A220627 Prime numbers that are not Brazilian. 14
 2, 3, 5, 11, 17, 19, 23, 29, 37, 41, 47, 53, 59, 61, 67, 71, 79, 83, 89, 97, 101, 103, 107, 109, 113, 131, 137, 139, 149, 151, 163, 167, 173, 179, 181, 191, 193, 197, 199, 223, 227, 229, 233, 239, 251, 257, 263, 269, 271, 277, 281, 283, 293, 311, 313, 317 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS These are primes not in A085104 (Brazilian primes). Primes that are not repunit in any base b >= 2 with three or more digits. LINKS T. D. Noe, Table of n, a(n) for n = 1..1000 Bernard Schott, Les nombres brĂ©siliens, Quadrature, no. 76, avril-juin 2010, pages 30-38; included here with permission from the editors of Quadrature. MATHEMATICA brazBases[n_] := Select[Range[2, n - 2], Length[Union[IntegerDigits[n, #]]] == 1 &]; Select[Range[2, 1000], PrimeQ[#] && brazBases[#] == {} &] (* T. D. Noe, Dec 26 2012 *) PROG (Python) from sympy.ntheory.factor_ import digits from sympy import isprime, primerange def B(n):     l=[]     for b in range(2, n - 1):         d=digits(n, b)[1:]         if max(d)==min(d): l.append(n)     return l print([n for n in primerange(2, 1001) if not B(n)]) # Indranil Ghosh, Jun 22 2017 (PARI) isok(p) = {if (isprime(p), for (b=2, p-1, my(d=digits(p, b), md=vecmin(d)); if ((#d > 2) && (md == 1) && (vecmax(d) == 1), return (0)); ); return (1); ); } \\ Michel Marcus, Apr 30 2021 CROSSREFS Cf. A085104. Sequence in context: A044042 A175179 A040060 * A040083 A045308 A245639 Adjacent sequences:  A220624 A220625 A220626 * A220628 A220629 A220630 KEYWORD nonn,base AUTHOR Bernard Schott, Dec 17 2012 STATUS approved

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Last modified August 13 17:37 EDT 2022. Contains 356107 sequences. (Running on oeis4.)