fred rosenberger wrote:My code takes (about) 2 seconds to compute which numbers below 28123 are abundant.
Same.
It then speeds through the computation in about another 2 seconds.
It takes my code just over a second to find 265 numbers that can't be the sum of abundant numbers looking in the first 500.
It takes almost 5 seconds to find 505 numbers that can't be the sum of abundant numbers looking in the first 1000.
I'm not sure why it takes four times longer to look in 1000 numbers than 500, except that their values are larger, so we're looking at more possible addends.
There's got to be a shortcut I don't see.