Sunday, May 12, 2013

The Four Power Days

Today, May 5 is written 5/12 in the US and 512 is a power of 2, it's \(2^9\). I tweeted that and received a rapid reply from Peter Inglesby that in UK-style dates it's 12/5 which is 125 which is \(5^3\). Which made me wonder whether there were other dates that had the same property in the US and UK on the same day.

Peter wrote a quick script:
and determined that there are four such dates:

March 24: US 3/24; \(324 = 18^2\). UK 24/3; \(243 = 3^5\)

May 12: US 5/12; \(512 = 2^9\). UK 12/5; \(125 = 5^3\)

June 25: US 6/25; \(625 = 5^4\). UK 25/6; \(256 = 2^8\)

December 5: US 12/5; \(125 = 5^3\). UK 5/12. \(512 = 2^9\)

Now I just need to think up a mystical significance to this, start a religion and retire on the proceeds.

1 comment:

Ralph Corderoy said...

I like Python, but the shell, in this case bash, can answer it too.

seq 0 365 | xargs -I_ date -d '2012-01-01 + _ days' +'%-m%-d %-d%-m' |
sed "\$(echo {1,{2..55}}' '{2,{3..11}}^pc | dc | awk '\$0 >= 11 && \$0 <= 3112' | sort -nu | sed 's#.*#/\\<&\\>/s/\$/+/;#')" |
sed -n 's/++\$//p'