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

Author

Clark Kimberling, May 29 2011

Keywords

• nonn

Comments

See A191203.

Examples

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

Links

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

Crossrefs

Cf. A191203.

Programs

Mathematica

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