Talk:Zumkeller numbers: Difference between revisions
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m (→Why this limitation in c++: added examples) |
(→Why this limitation in c++: first occurrences of non Zumkeller numbers with many divisors like 58896 with 30 divisors) |
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if (n % 2 || d.size() >= 24) |
if (n % 2 || d.size() >= 24) |
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return true;</pre> |
return true;</pre> |
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99504 has |
99504 has 30 divisors and is not a zumkeller number.<BR> |
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Testet with GO version: |
Testet with GO version: |
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<lang go>func main() { |
<lang go>func main() { |
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99500 99504 99510 99512 99516 </pre> |
99500 99504 99510 99512 99516 </pre> |
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Checked the first 100,000 zumkeller numbers.<BR> |
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First occurence of Non-Zumkeller number with count of divisors |
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<pre> |
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Div |
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count number |
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12 738 |
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16 7544 |
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18 3492 |
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20 56816 |
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24 14184 |
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30 58896 |
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36 236448</pre> |
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[[user horsth|Horsth]] 06:56, 9 May 2021 (UTC) |
[[user horsth|Horsth]] 06:56, 9 May 2021 (UTC) |
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Revision as of 08:45, 10 May 2021
Why this limitation in c++
// if we get here and n is odd or n has at least 24 divisors it's a zum!
if (n % 2 || d.size() >= 24)
return true;
99504 has 30 divisors and is not a zumkeller number.
Testet with GO version:
<lang go>func main() {
fmt.Println("The first 220 Zumkeller numbers are:")
for i, count := 99500, 0; count < 5; i++ {
if isZumkeller(i) {
fmt.Printf("%3d ", i)</lang>
99500 99510 99512 99516 99520
Testet with cpp version: <lang cpp> int main() {
cout << "First 220 Zumkeller numbers:" << endl;
vector<uint> zumz;
for (uint n = 99500; zumz.size() < 5; n++)
if (isZum(n))
zumz.push_back(n);
cout << zumz << endl << endl;
...
// if we get here and n is odd or n has at least 24 divisors it's a zum!
if (n % 2 || d.size() >= 29)
return true;</lang>
99500 99504 99510 99512 99516
Checked the first 100,000 zumkeller numbers.
First occurence of Non-Zumkeller number with count of divisors
Div count number 12 738 16 7544 18 3492 20 56816 24 14184 30 58896 36 236448
Horsth 06:56, 9 May 2021 (UTC)