login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A154726 Triangle read by rows in which row n lists: n, in the center of the row and the pairs of prime numbers that are equidistant to n, as shown below in the example. 12
1, 2, 3, 3, 4, 5, 3, 5, 7, 5, 6, 7, 3, 7, 11, 3, 5, 8, 11, 13, 5, 7, 9, 11, 13, 3, 7, 10, 13, 17, 3, 5, 11, 17, 19, 5, 7, 11, 12, 13, 17, 19, 3, 7, 13, 19, 23, 5, 11, 14, 17, 23, 7, 11, 13, 15, 17, 19, 23, 3, 13, 16, 19, 29, 3, 5, 11, 17, 23, 29 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
Triangle begins:
1
2
3
3 4 5
3 . 5 . 7
. . 5 6 7 . .
3 . . . 7 . . . 11
3 . 5 . . 8 . . 11 . 13
. . 5 . 7 . 9 . 11 . 13 . .
3 . . . 7 . . 10 . . 13 . . . 17
MAPLE
for n from 1 to 10 do for k from 1 to 2*n-1 do if(k=n or (isprime(k) and isprime(2*n-k)))then print(k):fi:od:od: # Nathaniel Johnston, Apr 18 2011
CROSSREFS
Sequence in context: A131282 A305296 A114544 * A325784 A244929 A302920
KEYWORD
easy,nonn,tabf
AUTHOR
Omar E. Pol, Jan 14 2009
EXTENSIONS
a(31)-a(70) from Nathaniel Johnston, Apr 18 2011
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 11:45 EDT 2024. Contains 371278 sequences. (Running on oeis4.)