68711380domain: NAppears in sequencesa(n) = 1^n + 2^n + 3^n + 4^n.at n=13A001551Sum of 13th powers: a(n) = Sum_{j=0..n} j^13.at n=4A181134a(n) = Sum_{k=0..floor(n/3)} k^n.at n=13A352982