Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                

Revision History for A307603

(Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

Showing entries 1-10 | older changes
Lexicographically earliest sequence with no duplicate term that produces only primes by the rounding technique explained in the Comments section.
(history; published version)
#18 by Joerg Arndt at Sat Apr 20 11:25:42 EDT 2019
STATUS

reviewed

approved

#17 by Michel Marcus at Sat Apr 20 11:09:52 EDT 2019
STATUS

proposed

reviewed

#16 by Rémy Sigrist at Sat Apr 20 10:36:12 EDT 2019
STATUS

editing

proposed

#15 by Rémy Sigrist at Sat Apr 20 10:36:04 EDT 2019
CROSSREFS

Cf. A173919 (Numbers that are prime or one less than a prime.).

STATUS

approved

editing

Discussion
Sat Apr 20
10:36
Rémy Sigrist: += cf.
#14 by N. J. A. Sloane at Fri Apr 19 10:28:23 EDT 2019
STATUS

editing

approved

#13 by N. J. A. Sloane at Fri Apr 19 10:28:11 EDT 2019
COMMENTS

"Rounding to the closest integer" might be seen as is ambiguous for decimal numbers like (k.5) where k is an integer. The tradition wants Here we round such numbers to be rounded to (k+1). This is the case here. Note that the The only occurrence of such a "rounding ambiguity" in the sequence happens with a(1) = 1 and a(2) = 5. Indeed, no more (k.5) "dilemmas" like that one will ever occur again as the integers 50, 500, 5000,... (that might produce together with the previous term k the decimal number k.50 or k.500 or k.5000...) cannot be part of the sequence; this is because 50, 500, 5000,... are not primes themselves (they end with 0) and neither are 51, 501, 5001,... (the can be divided they are divisible by 3).

EXAMPLE

The assembly [a(1),a(2)] is 1.5 which rounded to the closest integer upwards produces 2;

STATUS

proposed

editing

Discussion
Fri Apr 19
10:28
N. J. A. Sloane: Edited
#12 by Eric Angelini at Fri Apr 19 04:49:59 EDT 2019
STATUS

editing

proposed

Discussion
Fri Apr 19
10:25
N. J. A. Sloane: I don't agree with your "tradition". Some people prefer to round towards 0. So 1.5 -> 1.
#11 by Eric Angelini at Fri Apr 19 04:49:23 EDT 2019
COMMENTS

"Rounding to the closest integer" might be seen as ambiguous for decimal numbers like (k.5) where k is an integer. The tradition wants such numbers to be rounded to (k+1). This is the case here. Note that the only occurrence of such a "rounding ambiguity" in the sequence happens with a(1) = 1 and a(2) = 5. Indeed, no more (k.5) "dilemmas" like that one will ever occur again as the integers 50, 500, 5000,... (that might produce together with the previous term k the decimal number k.50 or k.500 or k.5000...) cannot be part of the sequence ; this is because 50, 500, 5000,... are not primes themselves (they end with 0) and neither are 51, 501, 5001,... neither (the can be divided by 3).

#10 by Eric Angelini at Fri Apr 19 04:44:22 EDT 2019
COMMENTS

"Rounding to the closest integer" might be seen as ambiguous for decimal numbers like (k.5) where k is an integer. The tradition wants such numbers to be rounded to (k+1). This is the case here. Note that the only occurrence of such a "rounding ambiguity" in the sequence happens with a(1) = 1 and a(2) = 5. Indeed, no more (k.5) "dilemmas" like that one will ever occur again as the integers 50, 500, 5000,... (that might produce together with the previous term k the decimal number k.50 or k.500 or k.5000...) cannot be part of the sequence becauses because 50, 500, 5000,... are not primes themselves (they end with 0) and so aren't 51, 501, 5001,... neither (the can be divided by 3).

#9 by Eric Angelini at Fri Apr 19 04:41:37 EDT 2019
COMMENTS

"Rounding to the closest integer" might be seen as ambiguous for decimal numbers like (k.5) where k is an integer. The tradition wants such numbers to be rounded to (k+1). This is the case here. Note that the only occurrence of such a "rounding ambiguity" in the sequence happens with a(1) = 1 and a(2) = 5. But Indeed, no more (k.5) "dilemmas" like this that one will ever occur again as the integers 50, 500, 5000,... (that might produce together with the previous term k the decimal number k.50 or k.500 or k.5000...) cannot be part of the sequence as becauses 50, 500, 5000,... are not primes themselves and so aren't 51, 501, 5001,... neither.