1,2

a(n) is least sum of coefficients of the 2 functions such that the form is a multiple of n. a(n) is a generalization of multiperfect number.

Table of n, a(n) for n=1..102.

a(multiperfect) = 1. a(prime) = 2 as 1*phi(prime) + 1*sigma(prime) and 1+1 = 2. For primes > 5, a(2*prime) = 4.

a(6) = 1 as 1*sigma(6) is a multiple of 6.

a(14) = 4 as 3*phi(14) + 1*sigma(14) = 3*6 + 24 = 3*14, where 3+1 = 4.

Cf. A000010, A000203, A000396, A005820, A027687, A046060, A046061.

Sequence in context: A318882 A055020 A052435 * A210452 A240301 A289641

Adjacent sequences: A094698 A094699 A094700 * A094702 A094703 A094704

nonn

Walter Nissen, May 20 2004

approved