A191211 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 1+2x and 1+x^2 are in a.

1, 2, 3, 5, 7, 10, 11, 15, 21, 23, 26, 31, 43, 47, 50, 53, 63, 87, 95, 101, 107, 122, 127, 175, 191, 203, 215, 226, 245, 255, 351, 383, 407, 431, 442, 453, 491, 511, 530, 677, 703, 767, 815, 863, 885, 907, 962, 983, 1023, 1061, 1355, 1407, 1535, 1631, 1727, 1771, 1815, 1850, 1925, 1967, 2047, 2123, 2210, 2501

Offset

1,2

Comments

See A191203.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Example

1 -> 2,3 -> 5,7,10 ->

Mathematica

g = 11; Union[Flatten[NestList[{1 + 2 #, 1 + #^2} &, 1, g]]]
(* A191211; use g>10 to get all of first 60 terms *)

Prog

(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a191211 n = a191211_list !! (n-1)
a191211_list = f $ singleton 1 where
   f s = m : f (insert (2 * m + 1) $ insert (m ^ 2 + 1) s')
         where (m, s') = deleteFindMin s
-- Reinhard Zumkeller, Apr 18 2014

Crossrefs

Cf. A191203.

Sequence in context: A266679 A285257 A317407 * A263133 A346592 A254860

Adjacent sequences: A191208 A191209 A191210 * A191212 A191213 A191214

Keyword

nonn

Author

Clark Kimberling, May 29 2011

Status

approved