cp's OEIS Frontend

A025538 a(n) = (1/s(1) - 1/s(2) + ... + d/s(n+1)) * LCM{1, 2, ..., n}, where d = (-1)^n, s = A002944, i.e., s(k) = LCM of row k of Pascal's triangle.

%I A025538 #9 Sep 04 2019 17:38:38
%S A025538 1,0,1,1,3,9,10,66,135,395,396,4344,4345,56471,56486,56478,112957,
%T A025538 1920251,1920252,36484768,36484789,36484767,36484768,839149640,
%U A025538 839149645,4195748199,4195748208,12587244596,12587244597,365030093283,365030093284
%N A025538 a(n) = (1/s(1) - 1/s(2) + ... + d/s(n+1)) * LCM{1, 2, ..., n}, where d = (-1)^n, s = A002944, i.e., s(k) = LCM of row k of Pascal's triangle.
%F A025538 a(n) = A003418(n) * Sum_{k=1..n+1} (-1)^(k+1)/A002944(k). - _Sean A. Irvine_, Sep 04 2019
%K A025538 nonn
%O A025538 0,5
%A A025538 _Clark Kimberling_
%E A025538 Title improved by _Sean A. Irvine_, Sep 04 2019