# Tetrominoe

Today we will all be fortunate enough to experience a ‘once in a lifetime event’. At one point today, around midday, clocks and calendars will give a combined consecutive numerical reading of 12:34:56 07/08/09 – Which is believed to only occur once every 100 years.

Thus, at 34 minutes and 56 seconds past 12:00 hours (12 pm), on Friday the 7th of August 2009, we will experience a centennial moment in time in which the first zeroless pandigital number can be used to precisely pinpoint the exact date and time.

In layman’s terms: all nine numerical digits, which hold a value greater than zero and which make up all arithmetic equations, will present themselves at a single point in time, in numerical order from smallest to largest, via the most well known sequence of numbers in existence: 123456789.

12:34:56  07/08/09

Personally I find this to be incredibly interesting. Particularly because I do have an inclination and mild obsession with numerical sequences and geometric symmetry. Consequently, I found a few interesting facts and figures concerning this first zeroless pandigital numbered sequence. For those who do not know, a pandigital number is in fact “an integer that in a given base, has among its significant digits, each digit used in the base at least once” (Wikipedia.com, 2009).

In most instances, the number ‘777’ is considered to be one of luck. It is also considered to be a symbol of absolute perfection. As it so happens, this number has an evenly symmetrical number of solutions, in both descending and ascending order, using the numbers 123456789 and by only ‘adding’ and ‘subtracting’. The solutions are (Martin Gardner, 02 June 2009):

Ascending                                                          Descending

– 12 – 3 + 4 + 5 – 6 + 789 = 777              – 9 – 8 + 765 – 4 + 32 + 1 = 777

– 12 + 3 – 4 – 5 + 6 + 789 = 777               98 + 7 + 654 – 3 + 21 = 777

Have you ever wondered what it would look like to display all the numbers from 1 through to 9 on an abacus? Well, here is your answer:

How about displaying this ascending zeroless pandigital sequence in Roman numerals? Here we go:

I, II, III, IV, V, VI,IIV,IIIV,IIIV,X,XI,XII

Here are a few interesting facts relating to numbers 1 through 9 courtesy of Richard Phillips’ book ‘Numbers’:

1. The letters A, B, C, D, E, M, T, U, V, W and Y all have one line of symmetry.

2. The number 2 is a prime number and is the only even prime number.

3. There are three barleycorns in an inch, three feet in a yard, and three miles in a league.

4. The word four has four letters. In the English language there is no other number whose number of letters is equal to its value.

5. There are only five possible tetrominoes. A tetromino is a shape made by joining together four squares. The game Tetris is based on the assembly of tetrominoes.

6. There are six feet in a fathom. A fathom is a unit of length used mainly by sailors. It equals 1.8288 metres.

7. The Seven Deadly Sins are avarice, envy, gluttony, lust, pride, sloth and wrath (listed in alphabetical order).

8. In the game of pool the Eight Ball is a black ball with the number 8. The expression `behind the eight ball’ means to be in a difficult or baffling situation.

9. There are nine major planets in the solar system, Beethoven wrote nine symphonies, and a cat is said to have nine lives.

I wish you all a very numerically filled and happy zeroless pandigital day!

Until the next time “Milieunairs”!