OFFSET
1,2
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
E. Angelini, a(n) shows one of the digits of a(n-1)-1, Nov 02 2014.
PROG
(PARI) {u=0; a=1; for(n=1, 99, print1(a", "); u+=1<<a; D=Set(if(a>1, digits(a-1))); for(k=2, 9e9, bittest(u, k)&&next; #setintersect(D, Set(digits(k)))||next; a=k; break))}
(Haskell)
import Data.List (intersect, delete)
a249591 n = a249591_list !! (n-1)
a249591_list = 1 : f 1 [2..] where
f x zs = g zs where
g (y:ys) = if null $ show y `intersect` show (x - 1)
then g ys else y : f y (delete y zs)
-- Reinhard Zumkeller, Nov 02 2014
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Eric Angelini and M. F. Hasler, Nov 01 2014
STATUS
approved