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 A383003 #12 Apr 12 2025 09:37:38
%S A383003 1,-1,10,-67,626,-7745,117650,-2097671,43046803,-999990009,
%T A383003 25937424602,-743008621115,23298085122482,-793714765724621,
%U A383003 29192926025441476,-1152921504875286543,48661191875666868482,-2185911559727678460653,104127350297911241532842
%N A383003 a(n) = Sum_{d|n} (-n)^(d-1).
%F A383003 a(n) = (1/n) * A383010(n).
%F A383003 a(n) = [x^n] Sum_{k>=1} log(1 + n*x^k) / k.
%F A383003 a(n) = [x^n] Sum_{k>=1} x^k / (1 + n*x^k).
%o A383003 (PARI) a(n) = sumdiv(n, d, (-n)^(d-1));
%Y A383003 Cf. A101561, A101562, A101563.
%Y A383003 Cf. A262843, A308814, A383010.
%Y A383003 Cf. A382998, A383012.
%K A383003 sign,easy
%O A383003 1,3
%A A383003 _Seiichi Manyama_, Apr 12 2025