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A199425 Number of distinct primes in rows 0 through n of the triangle in A199333. 4
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified March 4 05:42 EST 2021. Contains 341779 sequences. (Running on oeis4.)