Aliquot Sequence Research
2.0
Compute properties of the sum-of-proper-divisors function.
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This program implements an generaliztion of Conj. 1.4 of Pollack/Pomerance "Some problems of Erdos on the Sum of Divisors Function" Instead of estimating the natural density of only aliqout orphans this program also estimates the density of k-parent aliquot numbers n is a k-parent aliqout number iff there are k distinct natural numbers m st s(m) = n An aliquot orphan is a 0-parent aliquot number let delta-k be the estimated density of k-parent aliquot numbers and s(n) be the sum-of-proper-divisors function delta-k = 1/log(max_bound) * sum(forall a <= max_bound)( (a^(k-1) * e^(-a/s(a)) / k! * s(a)^k) ) More...
#include <assert.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
Macros | |
#define | UPPERPARENTS 16 |
Functions | |
uint64_t | s (uint64_t n) |
uint64_t | factorial (uint64_t n) |
double | accumulator (uint64_t start_a, char k, uint64_t *propSumDiv, long double *acc) |
int | main (int argc, char *argv[]) |
Variables | |
int | numChunks = 10 |
int | chunk_size |
int | buffer_size |
This program implements an generaliztion of Conj. 1.4 of Pollack/Pomerance "Some problems of Erdos on the Sum of Divisors Function" Instead of estimating the natural density of only aliqout orphans this program also estimates the density of k-parent aliquot numbers n is a k-parent aliqout number iff there are k distinct natural numbers m st s(m) = n An aliquot orphan is a 0-parent aliquot number let delta-k be the estimated density of k-parent aliquot numbers and s(n) be the sum-of-proper-divisors function delta-k = 1/log(max_bound) * sum(forall a <= max_bound)( (a^(k-1) * e^(-a/s(a)) / k! * s(a)^k) )