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A154725
Triangle read by rows in which row n lists 2n-1 terms: The pairs of prime numbers that are equidistant to n, with 0's inserted, as shown below in the example.
12
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 5, 0, 0, 0, 0, 3, 0, 0, 0, 7, 0, 0, 0, 0, 0, 0, 5, 0, 7, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 11, 0, 0, 0, 0, 3, 0, 5, 0, 0, 0, 0, 0, 11, 0, 13, 0, 0, 0, 0, 0, 0, 5, 0, 7, 0, 0, 0, 11, 0, 13, 0, 0, 0, 0
OFFSET
1,12
COMMENTS
Each entry of the n-th row is either 0 or a prime p from the 2n-th row of A002260 such that 2n-p is also prime. - Jason Kimberley, Jul 08 2012
LINKS
EXAMPLE
Triangle begins:
0
0, 0, 0
0, 0, 0, 0, 0
0, 0, 3, 0, 5, 0, 0
0, 0, 3, 0, 0, 0, 7, 0, 0
0, 0, 0, 0, 5, 0, 7, 0, 0, 0, 0
0, 0, 3, 0, 0, 0, 0, 0, 0, 0,11, 0, 0
0, 0, 3, 0, 5, 0, 0, 0, 0, 0,11, 0,13, 0, 0
0, 0, 0, 0, 5, 0, 7, 0, 0, 0,11, 0,13, 0, 0, 0, 0
0, 0, 3, 0, 0, 0, 7, 0, 0, 0, 0, 0,13, 0, 0, 0,17, 0, 0
From Jason Kimberley, Jul 08 2012: (Start)
Square array begins:
3, 3, 3, 0, 3, 3, 0, 3, 3, ...
0, 0, 0, 0, 0, 0, 0, 0, ...
5, 5, 5, 0, 5, 5, 0, 5, ...
0, 0, 0, 0, 0, 0, 0, ...
7, 7, 7, 0, 7, 7, 0, ...
0, 0, 0, 0, 0, 0, ...
0, 0, 0, 0, 0, 0, ...
0, 0, 0, 0, 0, ...
11, 11, 11, 0, 11, ...
0, 0, 0, 0, ...
13, 13, 13, 0, ...
0, 0, 0, ...
0, 0, 0, ...
0, 0, ...
17, 17, ...
0, ...
19, ...
MAPLE
for n from 1 to 10 do for k from 1 to 2*n-1 do if(not k=n and (isprime(k) and isprime(2*n-k)))then print(k):else print(0):fi:od:od: # Nathaniel Johnston, Apr 18 2011
KEYWORD
easy,nonn,tabf
AUTHOR
Omar E. Pol, Jan 14 2009
STATUS
approved