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A243298
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Numbers k such that k^9 - k^8 - k^7 - k^6 - k^5 - k^4 - k^3 - k^2 - k - 1 is prime.
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1
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4, 16, 18, 28, 76, 84, 88, 118, 146, 180, 258, 272, 274, 282, 316, 380, 384, 400, 462, 464, 468, 476, 548, 586, 588, 610, 616, 644, 646, 702, 708, 756, 786, 810, 826, 944, 954, 956, 988, 1000, 1016, 1052, 1104, 1138, 1166, 1178, 1194, 1212, 1226, 1240, 1258, 1356
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OFFSET
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1,1
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COMMENTS
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a(n) is even for all n.
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LINKS
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EXAMPLE
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4^9-4^8-4^7-4^6-4^5-4^4-4^3-4^2-4-1 = 174763 is prime. Thus, 4 is a member of this sequence.
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PROG
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(Python)
import sympy
from sympy import isprime
{print(n, end=', ') for n in range(10**4) if isprime(n**9-n**8-n**7-n**6-n**5-n**4-n**3-n**2-n-1)}
(PARI) for(n=1, 10^3, if(ispseudoprime(n^9-sum(i=0, 8, n^i)), print1(n, ", ")))
(Python)
from sympy import isprime
A243298_list, m = [], [362880, -1491840, 2464560, -2082240, 945000, -220248, 22560, -680, 1, -1]
for n in range(1, 10**5+1):
....for i in range(9):
........m[i+1]+= m[i]
....if isprime(m[-1]):
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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