OFFSET
1,2
COMMENTS
Permutation of the natural numbers when the triangle is seen flattened, inverse = A226387, see also A224401. - Reinhard Zumkeller, Jun 05 2013
LINKS
EXAMPLE
a(7) through a(10) = 5, 7, 11, 13 because 5 has not been used.
1;
2,3;
4,9,25;
5,7,11,13;
6,10,14,15,21;
8,27,125,343,1331,2197;
12,18,20,28,44,45,50;
16,81,625,2401,14641,28561,83521,130321;
PROG
(Haskell)
import Data.List ((\\))
a085612 n k = a085612_row n !! (k-1)
a085612_row n = a085612_tabf !! (n-1)
a085612_tabf = f 0 $ zip [1..] a046523_list where
f x zs'@(z:zs) = (map fst ys) : f (x + 1) (zs' \\ ys) where
ys = z : take x (filter ((== snd z) . snd) zs)
a085612_list = concat a085612_tabf
-- Reinhard Zumkeller, Jun 05 2013
(PARI) See Links section.
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Alford Arnold, Jul 04 2003
EXTENSIONS
More terms from Ray Chandler, Aug 21 2003
STATUS
approved