cp's OEIS Frontend

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.

A350700 a(n) is the number of 1's minus the number of 0's in A004685(n).

This page as a plain text file.
%I A350700 #37 Mar 17 2022 18:11:35
%S A350700 -1,1,1,0,2,1,-2,2,1,-2,4,1,-4,2,3,-2,6,3,-4,-3,3,-2,1,7,-4,-5,1,4,3,
%T A350700 5,-4,1,-4,4,1,-2,0,3,-6,-2,5,6,0,3,6,-1,11,-6,-9,3,2,-1,-1,-2,-5,6,4,
%U A350700 -7,8,0,-9,-4,10,3,-4,6,-7,6,-17,-1,-2,-5,1,4,-3
%N A350700 a(n) is the number of 1's minus the number of 0's in A004685(n).
%H A350700 Karl-Heinz Hofmann, <a href="/A350700/b350700.txt">Table of n, a(n) for n = 0..10000</a>
%F A350700 a(n) = A145037(A000045(n)) for n >= 1.
%F A350700 a(n) = 0 if and only if n is in A214852. - _Amiram Eldar_, Jan 22 2022
%e A350700 A004685(0) = 0; this term has 0 ones and 1 zero. So a(0) = 0 - 1 = -1.
%e A350700 A004685(7) = 1101; this term has 3 ones and 1 zero. So a(7) = 3 - 1 = 2.
%t A350700 a[n_] := Subtract @@ DigitCount[Fibonacci[n], 2, {1, 0}]; Array[a, 75, 0] (* _Amiram Eldar_, Jan 22 2022 *)
%o A350700 (Python) from sympy import fibonacci
%o A350700 print([(bin(fibonacci(n))[2:].count("1") - bin(fibonacci(n))[2:].count("0")) for n in range (0,100)])
%Y A350700 Cf. A000045, A004685, A011373, A145037, A177718, A214852.
%K A350700 sign,base
%O A350700 0,5
%A A350700 _Karl-Heinz Hofmann_, Jan 18 2022