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 A140589 #5 Dec 09 2020 02:25:51 %S A140589 2,-1,0,5,6,8,-7,-6,-4,0,17,18,20,24,32,-31,-30,-28,-24,-16,0,65,66, %T A140589 68,72,80,96,128,-127,-126,-124,-120,-112,-96,-64,0,257,258,260,264, %U A140589 272,288,320,384,512,-511,-510,-508,-504,-496,-480,-448,-384,-256,0,1025,1026,1028,1032 %N A140589 Triangle A(k,n) = (-2)^k+2^n read by rows. %C A140589 The flattened sequence a(A000217(k)+j)=A(k,j) obeys a(n+1)-2a(n)= -5, 2, 5, -4, -4, -23, 8, 8, 8, 17, -16, -16, -16, -16, -95, ..., which is a dispersion of 2, -4, -4, 8, 8, 8, ... (a signed version of A140513) with -5, 5, -23, 17, -95, 65,... The latter sequence is A(k,0)-2*A(k-1,k-1), an alternation of the negative of A140529 with each second element of A000051. %H A140589 Dana G. Korssjoen, Biyao Li, Stefan Steinerberger, Raghavendra Tripathi, and Ruimin Zhang, <a href="https://arxiv.org/abs/2012.04625">Finding structure in sequences of real numbers via graph theory: a problem list</a>, arXiv:2012.04625, Dec 08, 2020 %F A140589 A(k,n) = A000079(n)+A122803(k). %e A140589 Rows starting at k=0: (2), (-1,0); (5, 6, 8); (-7,-6,-4,0); (17,18,20,24,32);... %K A140589 sign,tabl %O A140589 0,1 %A A140589 _Paul Curtz_, Jul 06 2008 %E A140589 Edited by _R. J. Mathar_, Jul 08 2008