OFFSET
1,4
LINKS
N. J. A. Sloane, Table of n, a(n) for n = 1..10000
MATHEMATICA
Join[{0}, Table[(n-1)DivisorSigma[1, n]-n DivisorSigma[1, n-1], {n, 2, 60}]] (* Harvey P. Dale, Dec 30 2021 *)
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, May 30 2020
STATUS
approved