98250domain: NAppears in sequencesNumbers k such that phi(k) | sigma_10(k).at n=29A015768Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,51.at n=26A064262a(n) = Sum_k k!*A262292(n,k).at n=5A262291