A199425 Number of distinct primes in rows 0 through n of the triangle in A199333.

0, 0, 1, 2, 4, 5, 8, 10, 13, 17, 20, 24, 30, 35, 42, 49, 57, 63, 71, 80, 90, 99, 110, 121, 133, 145, 157, 170, 184, 197, 212, 227, 242, 258, 275, 292, 310, 327, 345, 364, 384, 404, 425, 446, 467, 489, 512, 535, 558, 581, 606, 630, 656, 682, 709, 736, 764

Offset

0,4

Links

Reinhard Zumkeller, Table of n, a(n) for n = 0..150

Prog

(Haskell)
import Data.List (union)
a199425 n = a199425_list !! n
a199425_list = f [] a199333_tabl where
   f ps (ts:tts) =  (length ps') : f ps' tts where
     ps' = ps `union` (take ((length ts - 1) `div` 2) $ tail ts)

Crossrefs

Cf. A199424, A126256.

Sequence in context: A000549 A191985 A126026 * A057129 A281898 A036404

Adjacent sequences: A199422 A199423 A199424 * A199426 A199427 A199428

Keyword

nonn

Author

Reinhard Zumkeller, Nov 09 2011

Status

approved