The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A083519 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A083519

Beginning with 1, a(i)*a(j) + 2 is prime for all i, j, i != j.
(history; published version)

#24 by Michael De Vlieger at Fri Oct 13 10:02:07 EDT 2023

STATUS

reviewed

approved

#23 by Joerg Arndt at Fri Oct 13 07:37:22 EDT 2023

STATUS

proposed

reviewed

#22 by Michel Marcus at Fri Oct 13 00:21:17 EDT 2023

STATUS

editing

proposed

#21 by Michel Marcus at Fri Oct 13 00:20:48 EDT 2023

EXAMPLE

9*1 + 2 = 11, 9*3 + 2 = 29, 9*5 + 2 = 47 are all prime numbers, primes, therefore we can say that a(4) = 9.

STATUS

proposed

editing

Discussion

Fri Oct 13

00:21

Michel Marcus: ok ?

#20 by Pontus von Brömssen at Thu Oct 12 16:07:25 EDT 2023

STATUS

editing

proposed

#19 by Pontus von Brömssen at Thu Oct 12 16:04:57 EDT 2023

NAME

Beginning with 1, a(i)*a(j) + 2 is prime for all i, j, i != j.

COMMENTS

For n >= 2, the last digit of a(n) is 5 or 9. - Pontus von Brömssen, Oct 12 2023

STATUS

approved

editing

Discussion

Thu Oct 12

16:07

Pontus von Brömssen: There was a similar (but incorrect) comment in a previous version (deleted in #5).

#18 by Susanna Cuyler at Sun Jan 13 08:48:29 EST 2019

STATUS

proposed

approved

#17 by Jianing Song at Sat Jan 12 23:55:30 EST 2019

STATUS

editing

proposed

Discussion

Sun Jan 13

03:30

Joerg Arndt: IMO: yes.

#16 by Jianing Song at Sat Jan 12 23:53:51 EST 2019

EXAMPLE

9*1 + 2 = 11, 9*3 + 2 = 29, 9*5 + 2 = 47 are all prime numbers, therefore we can say that a(4) = 9.

STATUS

proposed

editing

Discussion

Sat Jan 12

23:55

Jianing Song: Can we change the name to "Lexicographically earliest sequence such that a(i)*a(j) + 2 is prime for all i,j, i != j" ?

#15 by Chai Wah Wu at Sat Jan 12 22:01:07 EST 2019

STATUS

editing

proposed