OFFSET
1,1
LINKS
Reinhard Zumkeller, Rows n = 1..25 of triangle, flattened
EXAMPLE
. 1: 2 |
. 2: 2 3 | 5
. 3: 2 3 5 | 7
. 4: 2 3 5 7 | 17
. 5: 2 3 5 7 11 | 13 17 19 23
. 6: 2 3 5 7 11 13 | 17 19 23 29 31 41
. 7: 2 3 5 7 11 13 17 | 19 23 29 31 37 41 43 47 53
. 8: 2 3 5 7 11 13 17 19 | 23 29 31 37 41 43 47 53 59 61 67 .
PROG
(Haskell)
import Data.List (subsequences, nub, sort)
a256015 n k = a256015_tabf !! (n-1) !! (k-1)
a256015_row n = a256015_tabf !! (n-1)
a256015_tabf = map (sort . filter ((== 1) . a010051') . nub .
map sum . tail . subsequences) (tail $ inits a000040_list)
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Reinhard Zumkeller, Jun 01 2015
STATUS
approved