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A000734
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Boustrophedon transform of 1,1,2,4,8,16,32,...
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2
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1, 2, 5, 15, 49, 177, 715, 3255, 16689, 95777, 609875, 4270695, 32624329, 269995377, 2406363835, 22979029335, 234062319969, 2533147494977, 29027730898595, 351112918079175, 4470508510495609, 59766296291090577
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,2
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COMMENTS
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Binomial transform of A062272. - Paul Barry, Jan 21 2005
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LINKS
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Table of n, a(n) for n=0..21.
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 on transform, J. Combin. Theory, 17A 44-54 1996 (Abstract, pdf, ps).
N. J. A. Sloane, Transforms
Index entries for sequences related to boustrophedon transform
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FORMULA
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E.g.f.: (1+exp(2x))(sec(x)+tan(x))/2. - Paul Barry, Jan 21 2005
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PROG
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(Sage) # Algorithm of L. Seidel (1877)
def A000734_list(n) :
A = {-1:0, 0:1}; R = []
k = 0; e = 1; Bm = 1
for i in range(n) :
Am = Bm
A[k + e] = 0
e = -e
for j in (0..i) :
Am += A[k]
A[k] = Am
k += e
Bm += Bm
R.append(A[e*i//2]/2)
return R
A000734_list(22) # Peter Luschny, June 02 2012
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CROSSREFS
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Sequence in context: A149942 A149943 A079146 * A148366 A005751 A202182
Adjacent sequences: A000731 A000732 A000733 * A000735 A000736 A000737
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane, Simon Plouffe
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STATUS
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approved
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