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 A356387 #9 Aug 07 2022 15:36:51
%S A356387 1,1,2,2,-5,5,5,10,10,39,-39,-39,-13,13,13,26,26,-65,65,65,130,130,
%T A356387 -816,816,816,272,-272,-272,-544,-544,102,-102,-102,-34,34,34,68,68,
%U A356387 -170,170,170,340,340,1326,-1326,-1326,-442,442,442,884,884,-2210,2210,2210
%N A356387 a(n) is the product of all parts in negaFibonacci representation of n.
%C A356387 a(0) = 1 for the empty product.
%C A356387 See A273156 and A356388 for similar sequences.
%H A356387 Rémy Sigrist, <a href="/A356387/b356387.txt">Table of n, a(n) for n = 0..10946</a>
%H A356387 Wikipedia, <a href="https://en.wikipedia.org/wiki/NegaFibonacci_coding">NegaFibonacci coding</a>
%H A356387 <a href="/index/Z#Zeckendorf">Index entries for sequences related to Zeckendorf expansion of n</a>
%e A356387 For n = 11:
%e A356387 - using F(-k) = A039834(k):
%e A356387 - 11 = F(-1) + F(-4) + F(-7),
%e A356387 - so a(11) = F(-1) * F(-4) * F(-7) = 1 * -3 * 13 = -39.
%o A356387 (PARI) a(n) = { my (v=1); while (n, my (neg=0, pos=0, f); for (e=0, oo, f=fibonacci(-1-e); if (f<0, neg+=f, pos+=f); if (neg <=n && n <= pos, v*=f; n-=f; break))); return (v) }
%Y A356387 Cf. A039834, A059867, A215022, A273156, A356388.
%K A356387 sign,base
%O A356387 0,3
%A A356387 _Rémy Sigrist_, Aug 05 2022