[QUOTE=henryzz;446596]Which company do you trust more? Microsoft or a company you have never heard of?[/QUOTE]Is this a trick question?

:razz:

[QUOTE=Xyzzy;446445]We did some incredibly inelegant programming this evening and came up with this:[/QUOTE]User "[URL=http://www.mersenneforum.org/member.php?u=14625]jvang[/URL]" suggested some improvements, so we now have:[CODE]def isprime(n):
for i in xrange(2, int(n**0.5) + 1):
if n % i == 0: return False
return True
a = [2, 3, 5, 7]
b = [1, 3, 7, 9]
while a != []:
t = []
for x in a:
for y in b:
if isprime(x * 10 + y): t.append(x * 10 + y)
print a
a = t[/CODE][CODE][2, 3, 5, 7]
[23, 29, 31, 37, 53, 59, 71, 73, 79]
[233, 239, 293, 311, 313, 317, 373, 379, 593, 599, 719, 733, 739, 797]
[2333, 2339, 2393, 2399, 2939, 3119, 3137, 3733, 3739, 3793, 3797, 5939, 7193, 7331, 7333, 7393]
[23333, 23339, 23399, 23993, 29399, 31193, 31379, 37337, 37339, 37397, 59393, 59399, 71933, 73331, 73939]
[233993, 239933, 293999, 373379, 373393, 593933, 593993, 719333, 739391, 739393, 739397, 739399]
[2339933, 2399333, 2939999, 3733799, 5939333, 7393913, 7393931, 7393933]
[23399339, 29399999, 37337999, 59393339, 73939133][/CODE]

What about appending 2 digits at once?

[QUOTE=Stargate38;446486]That's not very energy efficient.[/QUOTE]
That is totally energy efficient. If you heat a wire (which in turn heats water, or directly your walls/floor/etc) you transform electrical energy into heat, without finding any prime and without factoring any number. All energy transforms into heat eventually, regardless of the fact that it is passing through your processor or to your boiler. One kilowatt spent on your computer produces exactly the same amount of heat as one kilowatt spent on your boiler. And more prime factors...

[QUOTE=LaurV;446701]That is totally energy efficient. If you heat a wire (which in turn heats water, or directly your walls/floor/etc) you transform electrical energy into heat ...[/QUOTE]But there are more efficient ways to heat your house. [spoiler]Heat pumps, aka a/c[/spoiler]

[QUOTE=retina;446702]But there are more efficient ways to heat your house. [spoiler]Heat pumps, aka a/c[/spoiler][/QUOTE]Indeed. The Official Monster Raving Loony Party manifesto pledge at one of the UK general elections was to address global warming by changing building regulations to require that all new buildings had to have air conditioning on the outside to cool the atmosphere.

[QUOTE=xilman;446710]...all new buildings had to have air conditioning on the outside to cool the atmosphere.[/QUOTE]
Love that! Wonderful! Haha... :tu: :w00t:

[QUOTE=xilman;446710]Indeed. The Official Monster Raving Loony Party manifesto pledge at one of the UK general elections was to address global warming by changing building regulations to require that all new buildings had to have air conditioning on the outside to cool the atmosphere.[/QUOTE]

While the majority of buildings in the UK don't have it on the inside.

[QUOTE=LaurV;446717]Love that! Wonderful! Haha... :tu: :w00t:[/QUOTE]Although a Raving Loony has never been elected to Parliament, several of their manifesto pledges have been enacted. Examples include lowering the voting age to 18, passports for pets and all-day pub opening hours.

[QUOTE=LaurV;446701]That is totally energy efficient. If you heat a wire (which in turn heats water, or directly your walls/floor/etc) you transform electrical energy into heat, without finding any prime and without factoring any number. All energy transforms into heat eventually, regardless of the fact that it is passing through your processor or to your boiler. One kilowatt spent on your computer produces exactly the same amount of heat as one kilowatt spent on your boiler. And more prime factors...[/QUOTE]

However, since I keep my computers in an outhouse because they make a noise like eighteen screaming banshees and disrupt the tranquility of my abode, all I end up with as a side-effect of my prime factors is a warm outhouse. It is occasionally suggested that I could grow cactuses or keep tortoises there, but I go to the outhouse fairly rarely and it seems sad to grow cactuses and keep tortoises that are only rarely seen.

[QUOTE=fivemack;446731]However, since I keep my computers in an outhouse because they make a noise like eighteen screaming banshees and disrupt the tranquility of my abode, all I end up with as a side-effect of my prime factors is a warm outhouse. It is occasionally suggested that I could grow cactuses or keep tortoises there, but I go to the outhouse fairly rarely and it seems sad to grow cactuses and keep tortoises that are only rarely seen.[/QUOTE]Pot plants?