A191283 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 2x and x(x+1)/2 are in a.

1, 2, 3, 4, 6, 8, 10, 12, 16, 20, 21, 24, 32, 36, 40, 42, 48, 55, 64, 72, 78, 80, 84, 96, 110, 128, 136, 144, 156, 160, 168, 192, 210, 220, 231, 256, 272, 288, 300, 312, 320, 336, 384, 420, 440, 462, 512, 528, 544, 576, 600, 624, 640, 666, 672, 768, 820, 840, 880, 903, 924, 1024, 1056, 1088, 1152, 1176, 1200, 1248, 1280, 1332

Offset

1,2

Comments

See A191203.

Links

Ivan Neretin, Table of n, a(n) for n = 1..10000

Example

1 -> 2 -> 3,4 -> 6,8,10 ->

Mathematica

g = 12; Union[Flatten[NestList[{2 #, (#^2 + #)/2} &, 1, g]]]
(* A191283; use g>10 to get all of first 60 terms *)

Crossrefs

Cf. A191203.

Sequence in context: A179971 A067069 A100497 * A341016 A200678 A088881

Adjacent sequences: A191280 A191281 A191282 * A191284 A191285 A191286

Keyword

nonn

Author

Clark Kimberling, May 29 2011

Status

approved