70453domain: NAppears in sequencesFourth row of Pascal-(1,3,1) array A081578.at n=19A081586Numbers n such that sigma_3(n) is divisible by square of cototient of n, while n is not a prime number.at n=29A091286a(n) = (4*n^3 - 6*n^2 + 14*n + 3)/3.at n=38A321124