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A231179
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Boustrophedon transform of nonnegative integers, cf. A001477.
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8
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0, 1, 4, 12, 36, 120, 462, 2058, 10472, 59976, 381770, 2673374, 20422908, 169020852, 1506427678, 14385323610, 146527700944, 1585801332848, 18171944693586, 219803766565366, 2798628476670180, 37414906698747564, 524019526485293894, 7672827408344428242
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OFFSET
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0,3
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COMMENTS
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a(n) = A231200(n) / 2.
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LINKS
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Reinhard Zumkeller, Table of n, a(n) for n = 0..400
Peter Luschny, An old operation on sequences: the Seidel transform
J. Millar, N. J. A. Sloane and N. E. Young, A new operation on sequences: the Boustrophedon transform, J. Combin. Theory, 17A 44-54 1996 (Abstract, pdf, ps).
Wikipedia, Boustrophedon transform
Index entries for sequences related to boustrophedon transform
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FORMULA
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a(n) = Sum_{k=1..n} k * A109449(n,k).
E.g.f.: x*exp(x)*(sec(x)+tan(x)). (After Sergei N. Gladkovskii in A000660.) - Peter Luschny, Oct 28 2014
a(n) = A000660(n) - A000111(n). - Sergei N. Gladkovskii, Oct 28 2014
a(n) ~ n! * exp(Pi/2) * 2^(n+1) / Pi^n. - Vaclav Kotesovec, Jun 12 2015
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MATHEMATICA
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a[n_] := n! SeriesCoefficient[x Exp[x] (1+Sin[x]) / Cos[x], {x, 0, n}];
Table[a[n], {n, 0, 23}] (* Jean-François Alcover, Jul 30 2018, after Peter Luschny *)
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PROG
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(Haskell)
a231179 n = sum $ zipWith (*) (a109449_row n) [0..]
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CROSSREFS
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Cf. A000737, A000660.
Sequence in context: A192205 A055395 A113990 * A331717 A192010 A252697
Adjacent sequences: A231176 A231177 A231178 * A231180 A231181 A231182
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KEYWORD
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nonn
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AUTHOR
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Reinhard Zumkeller, Nov 05 2013
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STATUS
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approved
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