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.

A105029 Write numbers in binary under each other, left justified, read diagonals in downward direction, convert to decimal.

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%I A105029 #19 May 08 2020 06:10:03
%S A105029 0,2,6,5,4,14,13,8,11,10,9,12,30,29,24,19,18,17,20,23,22,21,16,27,26,
%T A105029 25,28,62,61,56,51,34,33,36,39,38,37,32,43,42,41,44,47,46,45,40,35,50,
%U A105029 49,52,55,54,53,48,59,58,57,60,126,125,120,115,98,65,68,71,70
%N A105029 Write numbers in binary under each other, left justified, read diagonals in downward direction, convert to decimal.
%C A105029 All terms are distinct, but the numbers 2^m - 1 are missing.
%C A105029 a(n) = Sum_{k>=1} B(n+k-1,k)*2^(A103586(n)-k) where B(n,k) n>=1, k>=1 is the infinite array:
%C A105029 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,...
%C A105029 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,...
%C A105029 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,...
%C A105029 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,...
%C A105029 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,...
%C A105029 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,...
%C A105029 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,...
%C A105029 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,...
%C A105029 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,...
%C A105029 .......
%C A105029 where n-th row consists of binary expansion of n followed by 0's.
%C A105029 a(n) = A105025(n) iff A070939(n) = A103586(n), cf. A214489. - _Reinhard Zumkeller_, Jul 21 2012
%H A105029 Reinhard Zumkeller, <a href="/A105029/b105029.txt">Table of n, a(n) for n = 0..10000</a>
%H A105029 David Applegate, Benoit Cloitre, Philippe Deléham and N. J. A. Sloane, Sloping binary numbers: a new sequence related to the binary numbers [<a href="http://neilsloane.com/doc/slopey.pdf">pdf</a>, <a href="http://neilsloane.com/doc/slopey.ps">ps</a>].
%H A105029 David Applegate, Benoit Cloitre, Philippe Deléham and N. J. A. Sloane, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL8/Sloane/sloane300.html">Sloping binary numbers: a new sequence related to the binary numbers</a>, J. Integer Seq. 8 (2005), no. 3, Article 05.3.6, 15 pp.
%H A105029 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%e A105029 0
%e A105029 1
%e A105029 1 0
%e A105029 1 1
%e A105029 1 0 0
%e A105029 1 0 1
%e A105029 1 1 0
%e A105029 1 1 1
%e A105029 1 0 0 0
%e A105029 1 0 0 1
%e A105029 1 0 1 0
%e A105029 and reading the diagonals downwards we get 0, 10, 110, 101, 100, 1110, 1101, etc.
%o A105029 (Haskell)
%o A105029 import Data.Bits ((.|.), (.&.))
%o A105029 a105029 n = foldl (.|.) 0 $ zipWith (.&.) a000079_list $
%o A105029    map (\x -> (len + 1 - a070939 x) * x)
%o A105029        (reverse $ enumFromTo n (n - 1 + len))  where len = a103586 n
%o A105029 -- _Reinhard Zumkeller_, Jul 21 2012
%Y A105029 Cf. A102370, A105030, A105025, A105026, A105027, A105028, A105033.
%Y A105029 Cf. A000079, A070939, A103586.
%K A105029 nonn,base
%O A105029 0,2
%A A105029 _Benoit Cloitre_, Apr 03 2005