42 lines
1.4 KiB
C
42 lines
1.4 KiB
C
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/*=============================================================================
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This file is part of FLINT.
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FLINT is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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FLINT is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with FLINT; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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=============================================================================*/
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/******************************************************************************
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Copyright (C) 2011 Fredrik Johansson
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******************************************************************************/
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#include <math.h>
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#include "arith.h"
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double arith_bernoulli_number_size(ulong n)
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{
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double x;
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/* |B_n| < 2 */
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if (n <= 14)
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return 1.0;
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x = 2 + (n + 1) * log(n + 1) * 1.44269504088897; /* 1/log(2) */
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x -= n * 4.0941911703612822; /* log2(2*pi*e) */
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return x + 2;
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}
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