cp's OEIS Frontend

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.

A000733 Boustrophedon transform of partition numbers 1, 1, 1, 2, 3, 5, 7, ...

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%I A000733 #45 Jun 13 2022 03:02:52
%S A000733 1,2,4,10,30,101,394,1760,8970,51368,326991,2289669,17491625,
%T A000733 144760655,1290204758,12320541392,125496010615,1358185050788,
%U A000733 15563654383395,188254471337718,2396930376564860,32044598671291610
%N A000733 Boustrophedon transform of partition numbers 1, 1, 1, 2, 3, 5, 7, ...
%H A000733 John Cerkan, <a href="/A000733/b000733.txt">Table of n, a(n) for n = 0..482</a>
%H A000733 Peter Luschny, <a href="http://oeis.org/wiki/User:Peter_Luschny/SeidelTransform">An old operation on sequences: the Seidel transform</a>.
%H A000733 J. Millar, N. J. A. Sloane and N. E. Young, A new operation on sequences: the Boustrophedon transform, J. Combin. Theory, 17A (1996) 44-54 (<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 A000733 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>.
%H A000733 Wikipedia, <a href="https://en.wikipedia.org/wiki/Boustrophedon_transform">Boustrophedon transform</a>.
%H A000733 <a href="/index/Bo#boustrophedon">Index entries for sequences related to boustrophedon transform</a>
%e A000733 The array begins:
%e A000733                    1
%e A000733                1  ->   2
%e A000733            4  <-   3  <-   1
%e A000733        2  ->   6  ->   9  ->  10
%e A000733   30  <-  28  <-  22  <-  13  <-   3
%e A000733 - _John Cerkan_, Jan 26 2017
%t A000733 t[n_, 0] := If[n == 0, 1, PartitionsP[n-1]]; t[n_, k_] := t[n, k] = t[n, k - 1] + t[n-1, n-k]; a[n_] := t[n, n]; Array[a, 30, 0] (* _Jean-François Alcover_, Feb 12 2016 *)
%o A000733 (Haskell)
%o A000733 a000733 n = sum $ zipWith (*) (a109449_row n) (1 : a000041_list)
%o A000733 -- _Reinhard Zumkeller_, Nov 04 2013
%o A000733 (Python)
%o A000733 from itertools import count, accumulate, islice
%o A000733 from sympy import npartitions
%o A000733 def A000733_gen(): # generator of terms
%o A000733     yield 1
%o A000733     blist = (1,)
%o A000733     for i in count(0):
%o A000733         yield (blist := tuple(accumulate(reversed(blist),initial=npartitions(i))))[-1]
%o A000733 A000733_list = list(islice(A000733_gen(),40)) # _Chai Wah Wu_, Jun 12 2022
%Y A000733 Cf. A000041, A000751, A109449, A230957.
%K A000733 nonn
%O A000733 0,2
%A A000733 _N. J. A. Sloane_, _Simon Plouffe_