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 A140531 #23 Sep 30 2024 01:57:49 %S A140531 0,0,1,0,1,2,0,1,2,4,0,1,2,4,8,0,1,2,4,8,16,0,1,2,4,8,16,32,0,1,2,4,8, %T A140531 16,32,64,0,1,2,4,8,16,32,64,128,0,1,2,4,8,16,32,64,128,256,0,1,2,4,8, %U A140531 16,32,64,128,256,512,0,1,2,4,8,16,32,64,128,256,512,1024 %N A140531 Concatenate subsequences 0, 1, 2, 4, ..., 2^k. %C A140531 A sequence B is called a reluctant sequence of sequence A, if B is triangle array read by rows: row number k coincides with first k elements of the sequence A. Sequence A140531 is the reluctant sequence of A131577. - _Boris Putievskiy_, Dec 12 2012 %H A140531 Boris Putievskiy, <a href="http://arxiv.org/abs/1212.2732">Transformations Integer Sequences And Pairing Functions</a>, arXiv:1212.2732 [math.CO], 2012. %F A140531 a(n) = floor(2^(n-2-t*(t+1)/2)), where t=floor((-1+sqrt(8*n-7))/2), n>=1. - _Boris Putievskiy_, Dec 13 2012 %Y A140531 Cf. A000079, A059268. %K A140531 nonn,tabl %O A140531 0,6 %A A140531 _Paul Curtz_, Jul 03 2008