12587244596domain: NAppears in sequencesa(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.at n=27A025538