This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A230951 #15 Apr 18 2023 08:28:52 %S A230951 1,1,1,3,9,27,108,475,2421,13859,88254,617957,4720980,39070669, %T A230951 348225424,3325303894,33871280413,366573108019,4200618576106, %U A230951 50809739256049,646929695900154,8648812936664311,121132117170628444,1773647319453218254,27099334868109293640 %N A230951 Boustrophedon transform of Thue-Morse sequence A010059. %H A230951 Reinhard Zumkeller, <a href="/A230951/b230951.txt">Table of n, a(n) for n = 0..400</a> %H A230951 Peter Luschny, <a href="http://oeis.org/wiki/User:Peter_Luschny/SeidelTransform">An old operation on sequences: the Seidel transform</a> %H A230951 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 A230951 Wikipedia, <a href="http://en.wikipedia.org/wiki/Boustrophedon_transform">Boustrophedon transform</a> %H A230951 <a href="/index/Bo#boustrophedon">Index entries for sequences related to boustrophedon transform</a> %F A230951 a(n) = Sum_{k=0..n} A109449(n,k)*A010059(k). %o A230951 (Haskell) %o A230951 a230951 n = sum $ zipWith (*) (a109449_row n) $ map fromIntegral a010059_list %o A230951 (Python) %o A230951 from itertools import count, islice, accumulate %o A230951 def A230951_gen(): # generator of terms %o A230951 blist = tuple() %o A230951 for i in count(0): %o A230951 yield (blist := tuple(accumulate(reversed(blist), initial=i.bit_count()&1^1)))[-1] %o A230951 A230951_list = list(islice(A230951_gen(),30)) # _Chai Wah Wu_, Apr 17 2023 %Y A230951 Cf. A029885, A230950, A230952. %Y A230951 Cf. A010059, A109449. %K A230951 nonn %O A230951 0,4 %A A230951 _Reinhard Zumkeller_, Nov 03 2013