recursion won't work for some reason
- To: mathgroup at smc.vnet.net
- Subject: [mg124790] recursion won't work for some reason
- From: Roger Bagula <roger.bagula at gmail.com>
- Date: Tue, 7 Feb 2012 04:01:18 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
This recursion is translated from a FindSequenceFunction[]: won't work in version 8? Clear[a, n] a[1] == 1; a[2] == 1; a[3] == 1; a[4] == 5; a[5] == 4; a[6] == 3; a[7] == 25; a[8] == 23; a[9] == 22; a[10] == 149; a[11] == 130; a[12] == 110; a[n_] := a[n] = 64* a[-12 + n] + 69 *a[-9 + n] + 21 *a[-6 + n] - a[-3 + n] Table[a[n], {n, 1, 30}] I actually have hundreds like this that work with no problems...from version 5 and before. The FindSequenceFunction is: f[n_] = FindSequenceFunction[{1, 1, 1, 5, 4, 3, 25, 23, 22, 149, 130, 110, 785, 693, 623, 4389, 3880, 3397, 23977, 21115, 18684, 131893, 116502, 102680, 724705, 638985, 563949, 3980357, 3512812, 3098935, 21873593, 19295871, 17024690, 120159701, 106019274, 93536946, 660211505, 582473085, 513900795, 3627162981, 3200166736, 2823410521, 19928207945, 17582033699, 15512135608, 109487029365, 96597344158, 85225004732, 601533119489, 530715145745, 468234819865}, n] Table[f[n], {n, 1, 30}] {1, 1, 1, 5, 4, 3, 25, 23, 22, 149, 130, 110, 785, 693, 623, 4389, 3880, 3397, 23977, 21115, 18684, 131893, 116502, 102680, 724705, 638985, 563949, 3980357, 3512812, 3098935} The original sequence is a polynomial expansion: q[x_] = (-2 + 3 x - 8 x^3 + 8 x^4) f[x_] = ExpandAll[x^4*q[1/x]] a = Table[8^(1 + Floor[n/3])*SeriesCoefficient[ Series[1/f[x], {x, 0, 50}], n], {n, 0, 50}] Any help that you can give will be appreciated.
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- Re: recursion won't work for some reason
- From: Bob Hanlon <hanlonr357@gmail.com>
- Re: recursion won't work for some reason