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 A331002 #9 Jan 06 2020 09:15:07 %S A331002 0,0,-2,-2,1,1,-2,-2,2,2,-3,-3,3,3,-2,-2,3,3,-4,-4,2,2,-4,-4,4,4,-3, %T A331002 -3,5,5,-2,-2,6,6,-4,-4,4,4,-5,-5,5,5,-4,-4,5,5,-6,-6,3,3,-6,-6,6,6, %U A331002 -5,-5,6,6,-4,-4,6,6,-7,-7,3,3,-8,-8,4,4,-7,-7,7,7,-6 %N A331002 a(n) is the real part of f(n) (as defined in A330779). %H A331002 Rémy Sigrist, <a href="/A331002/b331002.txt">Table of n, a(n) for n = 0..10000</a> %H A331002 Rémy Sigrist, <a href="/A331002/a331002.gp.txt">PARI program for A331002</a> %F A331002 a(2*k+1) = a(2*k) for any k >= 0. %F A331002 a(2*k) = a(2*k-1) + A330779(2*k) * (-1)^k for any k > 0. %o A331002 (PARI) See Links section. %Y A331002 Cf. A330779. %K A331002 sign %O A331002 0,3 %A A331002 _Rémy Sigrist_, Jan 05 2020