1,2

See A102506 for a complete description. Note that sigma(n) is real iff n is in A004614.

Table of n, a(n) for n=1..77.

Re[Table[DivisorSigma[1, n, GaussianIntegers -> True], {n, 100}]]

Sequence in context: A117726 A172307 A108039 * A076340 A076345 A231349

Adjacent sequences: A103225 A103226 A103227 * A103229 A103230 A103231

sign

T. D. Noe, Jan 26 2005

approved