Showing posts with label letter. Show all posts
Showing posts with label letter. Show all posts

Sunday, 7 June 2026

Self-Fibonacci

Here is an interesting sequence generated by a hidden connection to Fibonacci based on the letter-number association shown in Table 1:


Table 1: source

The sequence is OEIS A129938:


A129938
: "Self-Fibonacci"; a(n) is the sum of the last nine terms. Sequence starts with 6, 9, 2, 15, 14, 1, 3, 3, 9 which are f, i, b, o, n, a, c, c, i if you consider a=1, b=2, c=3, ..., z=26.

The sequence begins 6, 9, 2, 15, 14, 1, 3, 3, 9, 62, 118, 227, 452, 889, 1764, 3527, 7051, 14099, 28189, ...

I only chanced upon this sequence because 28189, my diurnal age today, is a member. I've written about the various connections between numbers and letters in a post titled Days of the Year and Gematria back in August of 2021. The idea behind this sequence reminds me of my own approach described in a blog post titled Consolidating Fibonacci-like Numbers where I considered numbers whose digits following a Fibonacci pattern e.g. 21347:$$21347 \text{ where }2 + 1 =3, 1+3=4,3+4=7$$However, getting back to approach followed in OEIS A129938, an interesting "spin-off" could be that previously unnamed tribonacci sequences could be given memorable names. For example, using Table 1 we could write:$$ \text{ cat } \rightarrow \text{ c, a, t } \rightarrow \text{ 3, 1, 20 }$$and so the "cat" sequence becomes:$$3, 1, 20, 24, 45, 79, \dots$$Similarly we have:$$ \text{ dog } \rightarrow \text{ d, o, g } \rightarrow \text{ 4, 15, 7 }$$ So the "dog" sequence becomes:$$4, 15, 7, 26, 48, 81, \dots$$Silly I know but it would make for an interesting puzzle in Puzzle of the Day. The sequence doesn't have to be tribonacci, it could simply be Fibonacci-like. For example, we could ask why is the sequence 13, 5, 18, 23, 41, 65, ... egocentric? The answer is that:$$13, 5 \rightarrow \text{ m, e } \rightarrow \text{ me }$$Similarly, the sequence could be made of four or more seeds and a puzzle created. For example, we could ask what does this sequence 13, 9, 12, 11, 45, 77, ... and the Milky Way have in common? The answer is that the first four members of the sequence are the seeds to generate the future members of the sequence and we have:$$ 13, 9, 12, 11 \rightarrow \text{ m, i, l, k } \rightarrow \text{ milk}$$That's enough nonsense for the moment but let's not forget that there has always been a long-standing connection between letters of certain alphabets (Hebrew, Ancient Greek and Arabic for example) and numbers. With the English language the connection has weakened but it's still there and not just in the way shown in Table 1. There are other ways to assign values to letters in the English alphabet. Table 2 shows an alternative way that is more in keeping with the ancient languages.


Table 2: source

Friday, 21 July 2023

Numbers and Letters

This problem appeared in my email from Puzzle a Day:

There are 19 students in my university logic class. 15 of them play soccer, 16 play tennis, 12 like art, 5 enjoy history and 1 absolutely loves science. My university is situated at number 13 Main Street. My university’s logo is blue and it was designed ? years ago. How many years ago was my university’s logo designed?

I was clueless as to how to approach this problem even after I got the clue: Convert letters to numbers. What letters to convert was then the intermediate problem. I didn't know and looked at the solution:

My university’s logo was designed 25 years ago.

Each number in the question is the alphabetical position of the letter following it.

The final sentence is ‘My university’s logo is blue and it was designed ? years ago.’ The question mark is followed by the letter ‘y’, which is the 25th letter of the alphabet. This makes 25 the answer.

Let's add some formatting to the original question:

There are 19 students in my university logic class. 15 of them play soccer, 16 play tennis, 12 like art, 5 enjoy history and 1 absolutely loves science. My university is situated at number 13 Main Street. My university’s logo is blue and it was designed ? years ago. How many years ago was my university’s logo designed?

Once you see the "trick", it's easy and I'm forearmed now to face any future problems of a similar nature. Here's one of my own design:

There are 24 children in a class. 11 study German. \(x\) study Maths. What is the value of \(x\)?

The "trick" here is to determine how the numbers 24 and 11 are derived in the two sentences. There are 24 letters in the first sentence and 11 letters in the second sentence. There are ten letters in the third sentence and so "10 study Maths". The value of \(x\) is 10.

I mentioned Puzzle a Day in a post titled 2023 TO THE POWER OF 2023 in March 28th 2023. I should make more use of this resource. The emails were not going to my Primary email tab but to my Social tab and was missing them. I've redirected them to go to my Primary tab now.

Finally here are the correspondences that were used in both problems:

"a": 1, "b": 2,"c": 3,"d": 4,"e": 5, "f": 6, "g": 7,"h": 8,"i": 9,"j": 10,"k": 11,"l": 12,"m": 13, "n": 14,"o": 15,"p": 16,"q": 17,"r": 18,"s": 19,"t": 20,"u": 21,"v": 22,"w": 23,"x": 24,"y": 25,"z": 2