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A302718
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Number of cycles in the n-Apollonian network.
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2
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7, 119, 27850, 2635637428, 40538274896917926642, 18915440603912727411772352213199539580794, 4811072124719412065599148626063536230790419188877913496386013668865001860521888965
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OFFSET
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1,1
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COMMENTS
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a(8) has 165 decimal digits and a(9) has 331 decimal digits. - Andrew Howroyd, Sep 09 2019
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LINKS
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PROG
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(PARI)
P(c, d)={[2*d^3 + 7*d^2 + (6*c + 2)*d + 2*c, 3*d^2 + 5*d + (c + 1)]}
R(c, d)={16*d^3 + (9*c + 51)*d^2 + (30*c + 27)*d + (3*c^2 + 9*c + 4)}
a(n)={my(s=1, c=0, d=0); for(i=1, n, s = 3*s + R(c, d); [c, d]=P(c, d)); s} \\ Andrew Howroyd, Sep 10 2019
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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