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
Keywords
Examples
1 -> 2,3 -> 5,7,10 ->
Links
- Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
Crossrefs
Cf. A191203.
Programs
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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
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Mathematica
g = 11; Union[Flatten[NestList[{1 + 2 #, 1 + #^2} &, 1, g]]] (* A191211; use g>10 to get all of first 60 terms *)
Comments