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A068396
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n-th prime minus its reversal.
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4
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0, 0, 0, 0, 0, -18, -54, -72, -9, -63, 18, -36, 27, 9, -27, 18, -36, 45, -9, 54, 36, -18, 45, -9, 18, 0, -198, -594, -792, -198, -594, 0, -594, -792, -792, 0, -594, -198, -594, -198, -792, 0, 0, -198, -594, -792, 99, -99, -495
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OFFSET
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1,6
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COMMENTS
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All terms are divisible by 9. - Zak Seidov, Jun 05 2021
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LINKS
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FORMULA
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EXAMPLE
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a(10) = 29 - 92 = -63;
a(20) = 71 - 17 = 54.
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MATHEMATICA
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#-IntegerReverse[#]& /@ Prime[Range[50]] (* Harvey P. Dale, Dec 20 2012 *)
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PROG
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(Haskell)
a068396 n = p - a004086 p where p = a000040 n
(PARI) a(n) = prime(n) - fromdigits(Vecrev(digits(prime(n)))); \\ Michel Marcus, Sep 27 2017
(Python)
from sympy import prime
def a(n): pn = prime(n); return pn - int(str(pn)[::-1])
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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