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A154724
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Triangle read by rows in which row n lists 2n-1 terms: n, in the center of the row and the pairs of prime numbers that are equidistant to n, with 0's inserted, as shown below in the example.
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13
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1, 0, 2, 0, 0, 0, 3, 0, 0, 0, 0, 3, 4, 5, 0, 0, 0, 0, 3, 0, 5, 0, 7, 0, 0, 0, 0, 0, 0, 5, 6, 7, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 7, 0, 0, 0, 11, 0, 0, 0, 0, 3, 0, 5, 0, 0, 8, 0, 0, 11, 0, 13, 0, 0, 0, 0, 0, 0, 5, 0, 7, 0, 9, 0, 11, 0, 13, 0, 0, 0, 0
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,3
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LINKS
| Nathaniel Johnston, Table of n, a(n) for n = 1..10000
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EXAMPLE
| Triangle begins:
. . . . . . . . . . . . . . .1
. . . . . . . . . . . . . 0, 2, 0
. . . . . . . . . . . .0, 0, 3, 0, 0
. . . . . . . . . . 0, 0, 3, 4, 5, 0, 0
. . . . . . . . .0, 0, 3, 0, 5, 0, 7, 0, 0
. . . . . . . 0, 0, 0, 0, 5, 6, 7, 0, 0, 0, 0
. . . . . .0, 0, 3, 0, 0, 0, 7, 0, 0, 0,11, 0, 0
. . . . 0, 0, 3, 0, 5, 0, 0, 8, 0, 0,11, 0,13, 0, 0
. . .0, 0, 0, 0, 5, 0, 7, 0, 9, 0,11, 0,13, 0, 0, 0, 0
. 0, 0, 3, 0, 0, 0, 7, 0, 0,10, 0, 0,13, 0, 0, 0,17, 0, 0
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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):else print(0):fi:od:od: # Nathaniel Johnston, Apr 18 2011
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CROSSREFS
| Cf. A000040, A154720-A154727.
Sequence in context: A076998 A173956 A083927 * A134402 A132440 A174712
Adjacent sequences: A154721 A154722 A154723 * A154725 A154726 A154727
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KEYWORD
| easy,nonn,tabf
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AUTHOR
| Omar E. Pol (info(AT)polprimos.com), Jan 14 2009
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