-279840domain: ZAppears in sequencesa(n) = 1 - n^4.at n=23A024002a(n) = Sum_{d|n, d==1 mod 4} d^4 - Sum_{d|n, d==3 mod 4} d^4.at n=22A050456Jordan function J_{-4} multiplied by n^4.at n=22A189922