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A138139 Triangle read by rows: row n contains n terms and each column lists the prime numbers A000040. 4
2, 2, 2, 2, 3, 2, 2, 3, 3, 2, 2, 3, 5, 3, 2, 2, 3, 5, 5, 3, 2, 2, 3, 5, 7, 5, 3, 2, 2, 3, 5, 7, 7, 5, 3, 2, 2, 3, 5, 7, 11, 7, 5, 3, 2, 2, 3, 5, 7, 11, 11, 7, 5, 3, 2, 2, 3, 5, 7, 11, 13, 11, 7, 5, 3, 2, 2, 3, 5, 7, 11, 13, 13, 11, 7, 5, 3, 2, 2, 3, 5, 7, 11 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Nathaniel Johnston, Table of n, a(n) for n = 1..10000

EXAMPLE

Triangle begins:

      2

     2,2

    2,3,2

   2,3,3,2

  2,3,5,3,2

MAPLE

A138139 := proc(n, k) return ithprime(min(k, n-k+1)): end: seq(seq(A138139(n, k), k=1..n), n=1..13); # Nathaniel Johnston, Apr 30 2011

CROSSREFS

Cf. A000040, A003983.

Sequence in context: A033618 A061357 A270966 * A259578 A266547 A127992

Adjacent sequences:  A138136 A138137 A138138 * A138140 A138141 A138142

KEYWORD

easy,nonn,tabl

AUTHOR

Omar E. Pol, Mar 09 2008, Mar 25 2008

STATUS

approved

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Last modified April 24 00:02 EDT 2019. Contains 322404 sequences. (Running on oeis4.)