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A271226
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a(n) = (A271222(n)^2 + 2)/3^n, n >= 0.
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2
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2, 2, 3, 1, 43, 201, 67, 1289, 2278, 14662, 53782, 171798, 57266, 312537, 104179, 7353209, 14081926, 94917254, 148495259, 338541478, 2498895558, 832965186, 277655062, 45869694854, 90480235883, 230874654662
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OFFSET
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0,1
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COMMENTS
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a(n) is an integer because b(n) = A271222(n) satisfies b(n)^2 + 2 == 0 (mod 3^n), n >= 0.
See A268924 for details, links and references.
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LINKS
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FORMULA
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a(n) = (b(n)^2 + 2)/3^n, n >= 0, with b(n) = A271222(n).
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EXAMPLE
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a(0) = (0^2 + 2)/1 = 2.
a(4) = (59^2 + 2)/3^4 = 43.
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PROG
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(PARI) b(n) = if (n, 3^n - truncate(sqrt(-2+O(3^(n)))), 0);
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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