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A190808 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 2x and 3x+1 are in a. 5
1, 2, 4, 7, 8, 13, 14, 16, 22, 25, 26, 28, 32, 40, 43, 44, 49, 50, 52, 56, 64, 67, 76, 79, 80, 85, 86, 88, 97, 98, 100, 104, 112, 121, 128, 130, 133, 134, 148, 151, 152, 157, 158, 160, 169, 170, 172, 176, 193, 194, 196, 200, 202, 208, 224, 229, 238, 241, 242, 256 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
See A190803.
LINKS
MATHEMATICA
h = 2; i = 0; j = 3; k = 1; f = 1; g = 9 ;
a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]] (* A190808 *)
b = a/2; c = (a - 1)/3; r = Range[1, 900];
d = Intersection[b, r] (* A190851 *)
e = Intersection[c, r] (* A190852 *)
PROG
(Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a190808 n = a190808_list !! (n-1)
a190808_list = f $ singleton 1
where f s = m : (f $ insert (2*m) $ insert (3*m+1) s')
where (m, s') = deleteFindMin s
-- Reinhard Zumkeller, Jun 01 2011
CROSSREFS
Sequence in context: A236217 A320628 A260488 * A359727 A018614 A176745
KEYWORD
nonn
AUTHOR
Clark Kimberling, May 20 2011
EXTENSIONS
a(55)=224 inserted by Reinhard Zumkeller, Jun 01 2011
STATUS
approved

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Last modified February 26 19:20 EST 2024. Contains 370352 sequences. (Running on oeis4.)