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 A074142 #13 Jan 12 2025 23:37:16
%S A074142 1,-1,-1,0,0,2,1,0,-2,-5,2,3,5,6,-10,-12,-9,11,32,11,-5,-55,-61,29,84,
%T A074142 129,9,-188,-232,-136,322,567,255,-354,-1185,-840,585,2038,2318,-594,
%U A074142 -3909,-4761,-929,7387,10441,3930,-11137,-23097,-12215,16547,44716,36786,-23108
%N A074142 a(n) is the coefficient of x^n in x/(1 + Sum_{k>=1} (1/2)*(prime(k+1) - 1)*x^k).
%C A074142 The series reciprocal to the series with coefficients in A005097 has (integer) coefficients with irregular signs and values. In contrast the series reciprocal to the series with coefficients = primes themselves has coefficients (A030018) with alternating signs and regular growth. The radius of convergence (defined from consecutive coefficients ratio) of that series is 0.686777834460.
%F A074142 G.f.: x / (1 + Sum_{i>=1} A005097(i)*x^i).
%Y A074142 Cf. A005097, A030018.
%K A074142 easy,sign
%O A074142 1,6
%A A074142 _Zak Seidov_, Sep 16 2002