## Names scores

Project Euler again, this time Python. The problem is to sort a list of 5000 names alphabetically then give them a value. For example “COLIN” is 3 + 15 + 12 + 9 + 14 = 53 and is the 938th item – so its value is 49714 (53*938).

## Find the sum of amicable numbers under 10000

Project Euler problem 21 is to find the sum of all amicable numbers under 10000. An amicable number is:

Let $d(n)$ be the sum of proper divisors of $n$ then $d(a)=b$ and $d(b)=a$ if $a!=b$ then $a$ and $b$ are amicable numbers.

## Sum a list of 50 digit numbers

Problem 13 is summing a list of fifty digit numbers. I used the gmp library and R to solve in 2 lines:

```library(gmp)

Not much more to say really. I forgot the problem asks for the first 10 digits, so my first answer was wrong.

## Product of 4 consecutive numbers

I’m beginning to like R. You can capture table data from a connection (a generalised file), one of which is the clipboard, to a data frame.

```problem.matrix <-

## Asus X541S

My wife’s laptop is an Asus X541SA – a fairly generic and inexpensive workhorse. With a Quad-Core N3710, 4Gb of RAM and a 1TB HDD. Unfortunately its ridiculously slow. Opening, switching and closing applications leaves time to make a cup of tea and clicking save in Word is likely to see a “(not responding)” caption in the title bar.

A quick look in task manager shows the HDD is perpetually at 100%. Having already tried a clean install of Windows 10, I figured an SSD might help. I got this 120 Gb SanDisk SSD, having used them before with good results.

What a difference it makes, the laptop is not only usable but responsive. While I doubt it would handle many games it can at least cope with Office and Firefox, which it couldn’t before.

## Flashing Nexus 9 factory image

This tablet was super fast when I got it but now it lags and drives me nuts. I’d seen someone post on Reddit that flashing the factory image helped so I gave it a go.

Factory images are available here along with good, clear instructions. One caveat, Arch needs super user for fastboot otherwise you get “< Waiting for device >”. For the same reason run flash-all.sh with sudo too.

As to whether or not it helped, it is hard to say but I feel it has. How do you measure something that is entirely subjective?

Edit. Its been a few days now and it is faster. Much faster and without lag. I’m unclear why though. I’m not completely familiar with Android’s architecture but wonder if it’s a combination of multiple updates being applied (this was I think Android 5.0 when bought) and accumulated futz.

## Some thoughts on Wireless charging

I bought an Anker PowerPort Qi 10 inductive charger from Amazon (£13.99). I’ve seen a few people online complaining that it isn’t “wireless charging” because it’s still “plugged in” – a farcical complaint akin to suggesting that the device draw current from the ether.

Without doubt one of the most convenient devices I’ve used – put your phone on it and off it goes. The only things that are worth bearing in mind are that you need to use a fast charger if you want it to fast charge.