The restricted divisor function 
is the sum of the positive proper
divisors of a positive integer 
, given by
 |
where 
is the divisor function. For 
, 2, 
, the first few values are 0, 1, 1, 3, 1, 6, 1, 7, 4, 8,
1, 16, ... (OEIS A001065).
Restricted Divisor Function
See also
Divisor FunctionExplore with Wolfram|Alpha
References
Sloane, N. J. A. Sequence A001065/M2226 in "The On-Line Encyclopedia of Integer Sequences."Referenced on Wolfram|Alpha
Restricted Divisor FunctionCite this as:
Weisstein, Eric W. "Restricted Divisor Function." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/RestrictedDivisorFunction.html