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 A030620 #6 Jun 22 2017 17:45:12 %S A030620 0,0,1,1,1,1,1,1,2,3,3,2,2,3,3,3,3,3,2,2,2,2,2,2,2,2,1,1,1,1,0,0,-1, %T A030620 -2,-1,-1,0,0,0,0,0,0,0,0,0,-1,-2,-1,-1,-1,-1,-1,-1,-1,-1,-1,0,0,0,0, %U A030620 -1,-1,-1,-1,-1,0,0,0,0,1,0,0,-1,-1,-1,-1,-1,-2 %N A030620 a(n)=(# 3's)-(# 4's) in first n terms of A030604. %t A030620 Accumulate[Which[#==3,1,#==4,-1,True,0]&/@Flatten[IntegerDigits[#,6]&/@ Fibonacci[Range[2,30]]]] (* _Harvey P. Dale_, Jun 22 2017 *) %K A030620 sign %O A030620 1,9 %A A030620 _Clark Kimberling_