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 A356388 #8 Aug 07 2022 15:36:56 %S A356388 1,-1,-3,-3,3,-16,-16,-8,-8,8,24,24,-24,-210,-210,-105,-105,105,-42, %T A356388 -42,-21,-21,21,63,63,-63,336,336,168,168,-168,-504,-504,504,-7150, %U A356388 -7150,-3575,-3575,3575,-1430,-1430,-715,-715,715,2145,2145,-2145,-550,-550 %N A356388 a(n) is the product of all parts in negaFibonacci representation of -n. %C A356388 a(0) = 1 for the empty product. %C A356388 See A273156 and A356387 for similar sequences. %H A356388 Rémy Sigrist, <a href="/A356388/b356388.txt">Table of n, a(n) for n = 0..10946</a> %H A356388 Wikipedia, <a href="https://en.wikipedia.org/wiki/NegaFibonacci_coding">NegaFibonacci coding</a> %H A356388 <a href="/index/Z#Zeckendorf">Index entries for sequences related to Zeckendorf expansion of n</a> %e A356388 For n = 11: %e A356388 - using F(-k) = A039834(k): %e A356388 - -11 = F(-4) + F(-6), %e A356388 - so a(11) = F(-4) * F(-6) = -3 * -8 = 24. %o A356388 (PARI) a(n) = { my (v=1); n=-n; 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 A356388 Cf. A039834, A059867, A215023, A273156, A356387. %K A356388 sign,base %O A356388 0,3 %A A356388 _Rémy Sigrist_, Aug 05 2022