1800262812domain: NAppears in sequencesJordan function J_7(n).at n=20A069092a(n) = Sum_{d|n, d==1 mod 4} d^7 - Sum_{d|n, d==3 mod 4} d^7.at n=20A321823a(n) = Sum_{d|n, n/d==1 mod 4} d^7 - Sum_{d|n, n/d==3 mod 4} d^7.at n=20A321831