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A121965
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a(n) = (n-1)*a(n-1)-a(n-2).
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0
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1, 1, 1, 2, 7, 33, 191, 1304, 10241, 90865, 898409, 9791634, 116601199, 1506023953, 20967734143, 313009988192, 4987192076929, 84469255319601, 1515459403675889, 28709259414522290
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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COMMENTS
| Essentially the same as A058797.
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REFERENCES
| Eugene Jahnke and Fritz Emde, Table of Functions with Formulae and Curves, (1945), page 144.
Isak Hilmarsson, Ingibjorg Jonsdottir, Steinunn Sigurdardottir and Sigridur Vidarsdottir, Wilf-classification of mesh patterns of short length, http://skemman.is/stream/get/1946/9181/22991/4/Wilf-classification_of_mesh_patterns_of_short_length.pdf.
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FORMULA
| a(n) = ( J_n(2)*Y_0(2) - J_0(2)*Y_n(2) )/( J_1(2)* Y_0(2) - J_0(2)*Y_1(2) ) where J and Y are Bessel functions.
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MATHEMATICA
| Needs["DiscreteMath`RSolve`"]; Clear[f]; f[n_Integer] = Module[{a}, a[n] /.RSolve[{a[n] == (n - 1)*a[n - 1] - a[n - 2], a[0] == 0, a[1] == 1}, a[n], n][[1]] // Simplify]
// ToRadicals Table[Floor[N[f[n]]], {n, 0, 25}]
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CROSSREFS
| Cf. A106174, A007754, A056921 (bisection).
Sequence in context: A186760 A162661 A104981 * A058797 A006595 A179525
Adjacent sequences: A121962 A121963 A121964 * A121966 A121967 A121968
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KEYWORD
| nonn,less
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AUTHOR
| Roger Bagula (rlbagulatftn(AT)yahoo.com), Sep 02 2006
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EXTENSIONS
| Values (with rounding errors) and offset corrected by the Assoc. Eds. of the OEIS, Mar 27 2010
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