20100329, 16:46  #12 
"Ben"
Feb 2007
2·5·7·47 Posts 
update...
Code:
found primes in range 30000000000 to 31000000000 in elapsed time = 5.4245 sum of squares complete in elapsed time = 7.1620, sum is 416903941002774697723222981803 found primes in range 31000000000 to 32000000000 in elapsed time = 5.5802 **** 31252968359 is 0 mod 1000000000 **** sum of squares complete in elapsed time = 7.1759, sum is 457955303775896882861615585442 found primes in range 32000000000 to 33000000000 in elapsed time = 5.5252 sum of squares complete in elapsed time = 7.1461, sum is 501598601070515778427418232428 Code:
found primes in range 47000000000 to 48000000000 in elapsed time = 5.5268 sum of squares complete in elapsed time = 7.0336, sum is 1519756369296424391708040649758 found primes in range 48000000000 to 49000000000 in elapsed time = 5.4239 sum of squares complete in elapsed time = 7.0347, sum is 1615357580573805620690452754303 found primes in range 49000000000 to 50000000000 in elapsed time = 5.4835 **** 49460594569 is 0 mod 1410065408 **** sum of squares complete in elapsed time = 6.8852, sum is 1714863031171407826702942323341 found primes in range 50000000000 to 51000000000 in elapsed time = 5.4299 Last fiddled with by bsquared on 20100329 at 16:51 Reason: another update 
20100329, 22:57  #13 
"Ben"
Feb 2007
CDA_{16} Posts 
Right on cue
we have this result:
Code:
found primes in range 1915000000000 to 1916000000000 in elapsed time = 5.0965 **** 1915014433303 is 0 mod 1215752192 **** sum of squares complete in elapsed time = 5.0550, sum is 83903230112675776937166385335972895 
20100330, 02:35  #14 
"Ben"
Feb 2007
2×5×7×47 Posts 
That should have been 1e9 every 10 sec, but the time estimate is still about right. It's probably silly, but a run to 20 trillion is ongoing...
Here was the sum of all prime squares up to 1915014433303: 83775363722237720731978600000000000 I'm keeping a file with the sums every 1e9, in case anyone wants to extend the sequence after I get tired of it or for double checks. Last fiddled with by bsquared on 20100330 at 02:38 Reason: whoops... 
20100330, 12:57  #15 
"Ben"
Feb 2007
110011011010_{2} Posts 
I see that the death knell of this thread has been sounded
Maybe the 12th member of the sequence is still of interest... 
20100330, 15:07  #16 
Aug 2006
3×5^{2}×79 Posts 

20100330, 15:40  #17 
"Ben"
Feb 2007
2·5·7·47 Posts 
I have no problem doing so... but I'm not the "discoverer" of this sequence. I'll defer to you or davar55 if you would rather take the credit.
Last fiddled with by bsquared on 20100330 at 15:40 
20100330, 15:44  #18 
Aug 2006
3·5^{2}·79 Posts 
I PM'd davar55.

20100330, 15:52  #19 
"Ben"
Feb 2007
3290_{10} Posts 
Also, this sequence could now be greatly extended.

20100330, 16:12  #20  
Aug 2006
3×5^{2}×79 Posts 
Quote:
As it happens I never computed that sequence for these calculations  I used pure modular arithmetic. (If I used BCD I could have avoided this while keeping speed high...) Last fiddled with by CRGreathouse on 20100330 at 16:14 

20100330, 17:01  #21  
"Ben"
Feb 2007
6332_{8} Posts 
Quote:
Yeah, that's definitely faster, but using pure modular arithmetic would require you to start the sum over for each new modulus, right? 

20100330, 17:17  #22 
Aug 2006
5925_{10} Posts 
Right. You could do two modili at a time without much penalty, though, with appropriate lookup tables and bit operations. Note that you only need to compare (and hence reduce) every 8 primes, each term (other than the first) has index = 5 (mod 8).
Last fiddled with by CRGreathouse on 20100330 at 17:23 
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