Chowla numbers: Difference between revisions

=={{header|Maple}}==

<lang Maple>ChowlaFunction := n -> NumberTheory:-SumOfDivisors(n) - n - 1;

PrintChowla := proc(n::posint) local i;

printf("Integer : Chowla Number\n");

for i to n do

printf("%d : %d\n", i, ChowlaFunction(i));

end do;

end proc:

countPrimes := n -> nops([ListTools[SearchAll](0, map(ChowlaFunction, [seq(1 .. n)]))]);

findPerfect := proc(n::posint) local to_check, found, k;

to_check := map(ChowlaFunction, [seq(1 .. n)]);

found := [];

for k to n do

if to_check(k) = k - 1 then

found := [found, k];

end if;

end do;

end proc:

PrintChowla(37);

countPrimes(100);

countPrimes(1000);

countPrimes(10000);

countPrimes(100000);

countPrimes(1000000);

countPrimes(10000000);

findPerfect(35000000)</lang>

{{Out}}

<pre>

Integer : Chowla Number

1 : -1

2 : 0

3 : 0

4 : 2

5 : 0

6 : 5

7 : 0

8 : 6

9 : 3

10 : 7

11 : 0

12 : 15

13 : 0

14 : 9

15 : 8

16 : 14

17 : 0

18 : 20

19 : 0

20 : 21

21 : 10

22 : 13

23 : 0

24 : 35

25 : 5

26 : 15

27 : 12

28 : 27

29 : 0

30 : 41

31 : 0

32 : 30

33 : 14

34 : 19

35 : 12

36 : 54

37 : 0

25

168

1229

9592

78498

664579

[6, 28, 496, 8128, 33550336]</pre>