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Boustrophedon transform of Thue-Morse sequence A010059.
5

%I #15 Apr 18 2023 08:28:52

%S 1,1,1,3,9,27,108,475,2421,13859,88254,617957,4720980,39070669,

%T 348225424,3325303894,33871280413,366573108019,4200618576106,

%U 50809739256049,646929695900154,8648812936664311,121132117170628444,1773647319453218254,27099334868109293640

%N Boustrophedon transform of Thue-Morse sequence A010059.

%H Reinhard Zumkeller, <a href="/A230951/b230951.txt">Table of n, a(n) for n = 0..400</a>

%H Peter Luschny, <a href="http://oeis.org/wiki/User:Peter_Luschny/SeidelTransform">An old operation on sequences: the Seidel transform</a>

%H 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 (<a href="http://neilsloane.com/doc/bous.txt">Abstract</a>, <a href="http://neilsloane.com/doc/bous.pdf">pdf</a>, <a href="http://neilsloane.com/doc/bous.ps">ps</a>).

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Boustrophedon_transform">Boustrophedon transform</a>

%H <a href="/index/Bo#boustrophedon">Index entries for sequences related to boustrophedon transform</a>

%F a(n) = Sum_{k=0..n} A109449(n,k)*A010059(k).

%o (Haskell)

%o a230951 n = sum $ zipWith (*) (a109449_row n) $ map fromIntegral a010059_list

%o (Python)

%o from itertools import count, islice, accumulate

%o def A230951_gen(): # generator of terms

%o blist = tuple()

%o for i in count(0):

%o yield (blist := tuple(accumulate(reversed(blist), initial=i.bit_count()&1^1)))[-1]

%o A230951_list = list(islice(A230951_gen(),30)) # _Chai Wah Wu_, Apr 17 2023

%Y Cf. A029885, A230950, A230952.

%Y Cf. A010059, A109449.

%K nonn

%O 0,4

%A _Reinhard Zumkeller_, Nov 03 2013