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### 11105 - Semi-prime H-numbers

Posted: **Tue Oct 17, 2006 6:04 pm**

by **coolguy**

according to my code the number of H primes in the range is 89070 and number of H semi primes is 117965 ........am i right ?? can anyone please verify .............

waiting to be helped ....

Posted: **Thu Oct 19, 2006 1:37 am**

by **david**

There are 89070 h-primes and 105753 h semi-primes in the range allowed.

### 11105ac

Posted: **Fri Oct 20, 2006 7:16 am**

by **coolguy**

thank u david for ur reply . i got it ac . i was counting repeats . now i maintain a set and get ac ..

bye bye

Posted: **Fri Nov 03, 2006 4:34 am**

by **cytmike**

Anybody knows a more efficient way to do this?

My code gets AC in 9.97s ....

Posted: **Fri Nov 03, 2006 4:58 pm**

by **helloneo**

cytmike wrote:Anybody knows a more efficient way to do this?

My code gets AC in 9.97s ....

I did something like sieve..

It runs 0.104 sec..

### help me.....

Posted: **Thu Jun 28, 2007 12:30 am**

by **chinmoy kanti dhar**

how can i determine a H prime.Is 49 is a H prime?plz help me by giving first 20 H prime.....

### Re: help me.....

Posted: **Thu Jun 28, 2007 1:34 pm**

by **Jan**

chinmoy kanti dhar wrote:
1. how can i determine a H prime. Is 49 is a H prime?

2. plz help me by giving first 20 H prime.....

1. Modified sieve will do.

2. The first 20 Hprime are...

Code: Select all

`5 9 13 17 21 29 33 37 41 49 53 57 61 69 73 77 89 93 97 101`

Hope these help.

Posted: **Wed Aug 01, 2007 12:16 pm**

by **jainal cse du**

Posted: **Tue Oct 16, 2007 5:14 pm**

by **lucky16g**

for sample input

789

i got ans 64

follower are my 64 H-semi-primes

can anyone tell me which two are not H-semi-primes

1 ) 5 5 =25

2 ) 5 9 =45

3 ) 5 13 =65

4 ) 5 17 =85

5 ) 5 21 =105

6 ) 5 29 =145

7 ) 5 33 =165

8 ) 5 37 =185

9 ) 5 41 =205

10 ) 5 49 =245

11 ) 5 53 =265

12 ) 5 57 =285

13 ) 5 61 =305

14 ) 5 69 =345

15 ) 5 73 =365

16 ) 5 77 =385

17 ) 5 89 =445

18 ) 5 93 =465

19 ) 5 97 =485

20 ) 5 101 =505

21 ) 5 109 =545

22 ) 5 113 =565

23 ) 5 121 =605

24 ) 5 129 =645

25 ) 5 133 =665

26 ) 5 137 =685

27 ) 5 141 =705

28 ) 5 149 =745

29 ) 5 157 =785

30 ) 9 9 =81

31 ) 9 13 =117

32 ) 9 17 =153

33 ) 9 21 =189

34 ) 9 29 =261

35 ) 9 33 =297

36 ) 9 37 =333

37 ) 9 41 =369

38 ) 9 49 =441

39 ) 9 53 =477

40 ) 9 57 =513

41 ) 9 61 =549

42 ) 9 69 =621

43 ) 9 73 =657

44 ) 9 77 =693

45 ) 13 13 =169

46 ) 13 17 =221

47 ) 13 21 =273

48 ) 13 29 =377

49 ) 13 33 =429

50 ) 13 37 =481

51 ) 13 41 =533

52 ) 13 49 =637

53 ) 13 53 =689

54 ) 13 57 =741

55 ) 17 17 =289

56 ) 17 21 =357

57 ) 17 29 =493

58 ) 17 33 =561

59 ) 17 37 =629

60 ) 17 41 =697

61 ) 21 21 =441

62 ) 21 29 =609

63 ) 21 33 =693

64 ) 21 37 =777

Posted: **Wed Oct 17, 2007 2:14 am**

by **Jan**

You are counting 441 and 693 twice!

Posted: **Wed Oct 17, 2007 6:06 am**

by **lucky16g**

thanks for your debug

there's very helfull for me

thanks a lot!!!

### 11105 - Semi-prime H-numbers

Posted: **Mon Aug 04, 2008 3:51 pm**

by **lnr**

5=5*1 so it is not a semi prime.

1 is unit.

### 11105 - Semi-prime H-numbers

Posted: **Mon Aug 04, 2008 7:07 pm**

by **lnr**

What is the difference between H-primes and H-semi-primes?

### 11105 - Semi-prime H-numbers

Posted: **Tue Feb 17, 2009 9:56 pm**

by **sazzadcsedu**

how to determine a particular number is only multiple of 2 number!!!

plz some give me some idea;

i remove number containing more than 2-(5,9,13,17.....)

but cant handle case like:-5*117=(5*9*17).

how to handle them?????

### Re: 11105 - Semi-prime H-numbers

Posted: **Wed Feb 18, 2009 4:36 pm**

by **helloneo**