Number sequences from 1 to 50 • page 2/4 • Off-Topic Discussion • lichess.org

FQT

#11

@Phil224 said in #9:

I don't think 3 is
Sorry, 3 is mirror number

@Phil224 said in #9: > I don't think 3 is Sorry, 3 is mirror number

Toscani

edited

#12

Referring to post #6: None of those numbers meet the criteria for caboose numbers, because caboose numbers are even numbers. The smallest caboose number is 2.
Even Numbers: Caboose Numbers
Odd Numbers: Engine Numbers (playful analogy)

Referring to post #8, 9: Palindromic numbers (or reverseward numbers) are indeed defined as numbers that read the same from left to right as they do from right to left. The definition applies to both single-digits and multi-digit numbers. : 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44.

Referring to post #3 & 10, Nice catch! Single Hole Numbers (Contains one "hole"). It's the space inside the number !
0: Contains 1 hole (the enclosed space in the middle).
4: Contains 1 hole (the enclosed area in the top part).
6: Contains 1 hole (the circular space at the bottom).
8: Contains 2 holes (the two enclosed spaces, one on top and one on the bottom).
9: Contains 1 hole (the circular space at the bottom).
Therefore, 1819 is a hole number with a total of 3 holes.

Referring to post #6: None of those numbers meet the criteria for caboose numbers, because caboose numbers are even numbers. The smallest caboose number is 2. Even Numbers: Caboose Numbers Odd Numbers: Engine Numbers (playful analogy) Referring to post #8, 9: Palindromic numbers (or reverseward numbers) are indeed defined as numbers that read the same from left to right as they do from right to left. The definition applies to both single-digits and multi-digit numbers. : 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44. Referring to post #3 & 10, Nice catch! Single Hole Numbers (Contains one "hole"). It's the space inside the number ! 0: Contains 1 hole (the enclosed space in the middle). 4: Contains 1 hole (the enclosed area in the top part). 6: Contains 1 hole (the circular space at the bottom). 8: Contains 2 holes (the two enclosed spaces, one on top and one on the bottom). 9: Contains 1 hole (the circular space at the bottom). Therefore, 1819 is a hole number with a total of 3 holes.

Phil224

edited

#13

@Toscani said in #12:

Referring to post #6: None of those numbers meet the criteria for caboose numbers, because caboose numbers are even numbers. The smallest caboose number is 2.

Oh, we must be talking about a different caboose number, “my” definition is that a number c n<c that n^2-n+41(which is c in this case) is always prime
There might be more values of c
https://m.youtube.com/watch?v=gM5uNcgn2NQ

@Toscani said in #12: > Referring to post #6: None of those numbers meet the criteria for caboose numbers, because caboose numbers are even numbers. The smallest caboose number is 2. Oh, we must be talking about a different caboose number, “my” definition is that a number c n<c that n^2-n+41(which is c in this case) is always prime There might be more values of c https://m.youtube.com/watch?v=gM5uNcgn2NQ

Ceromax22

#14

Catastrophic numbers: 9, 11, 2001...

Mate_on_f7

#15

quadratic residues mod 53 (that are not 52):
1 4 6 7 9 10 11 13 15 16 17 24 25 28 29 36 37 38 40 42 43 44 46 47 49

quadratic residues mod 53 (that are not 52): 1 4 6 7 9 10 11 13 15 16 17 24 25 28 29 36 37 38 40 42 43 44 46 47 49

1/9/1939

Referring to post #14 and #16: The term "catastrophic number" isn't commonly used in "mathematics" to describe a specific set of numbers or sequences between 1 and 50. Adding the year was over the number 50, but I understood.

Happy Numbers: 1, 7, 10, 13, 19, 23, 28, 31, 32, 44, 49 ...

Referring to post #14 and #16: The term "catastrophic number" isn't commonly used in "mathematics" to describe a specific set of numbers or sequences between 1 and 50. Adding the year was over the number 50, but I understood. Happy Numbers: 1, 7, 10, 13, 19, 23, 28, 31, 32, 44, 49 ...

Toscani

#18

Abundant numbers: 12, 18, 20, 24, 30, 36, 40, 42, 48 ...

Toscani

#19

https://youtu.be/GtOt7EBNEwQ?si=T-F0YaZabCecshXO

salmon_rushdie

#20

5 1 0 15 20 25 30 35 40 45 50

who can guess what this sequence is

5 1 0 15 20 25 30 35 40 45 50 who can guess what this sequence is