OFFSET
1,2
COMMENTS
A024816(n) is the sum of the non-divisors k of n for k=2,3,...,n-1.
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
MATHEMATICA
Differences[Table[Total[Complement[Range[n], Divisors[n]]], {n, 80}]] (* Harvey P. Dale, Mar 05 2013 *)
PROG
(PARI) a(n) = n + 1 + sigma(n) - sigma(n+1); \\ Michel Marcus, Jul 29 2017
CROSSREFS
KEYWORD
sign
AUTHOR
John W. Layman, Jul 30 2009
STATUS
approved