A138139 Triangle read by rows: row n contains n terms and each column lists the prime numbers A000040.

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

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