2,1

Reinhard Zumkeller, Table of n, a(n) for n = 2..797

(Haskell)

import Data.List (delete)

a253415 n = a253415_list !! (n-2)

a253415_list = f [2..] 1 where

f xs z = g xs where

g (y:ys) = if mod z' y > 0 then g ys else x : f xs' (z + y)

where xs'@(x:_) = delete y xs

z' = z + 2

-- Reinhard Zumkeller, Dec 31 2014

Cf. A095258, A095259, A253425 (run lengths).

Sequence in context: A278300 A034214 A317749 * A227401 A131813 A083038

Adjacent sequences: A253412 A253413 A253414 * A253416 A253417 A253418

nonn

Reinhard Zumkeller, Dec 31 2014

approved