A191290 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 2x+1 and x(x+1)/2 are in a.

1, 3, 6, 7, 13, 15, 21, 27, 28, 31, 43, 55, 57, 63, 87, 91, 111, 115, 120, 127, 175, 183, 223, 231, 241, 255, 351, 367, 378, 406, 447, 463, 483, 496, 511, 703, 735, 757, 813, 895, 927, 946, 967, 993, 1023, 1407, 1471, 1515, 1540, 1627, 1653, 1791, 1855, 1893, 1935, 1987, 2016, 2047, 2815, 2943, 3031, 3081, 3255, 3307, 3583

Offset

1,2

Comments

See A191203.

Links

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

Example

1 -> 3 -> 6,7 -> 13,15,21,28 ->

Mathematica

g=11; Union[Flatten[NestList[{1+2#, (#^2+#)/2} &, 1, g]]]
(* A191290; use g>9 to get all of first 60 terms *)

Crossrefs

Cf. A191203.

Sequence in context: A282354 A088146 A176301 * A137595 A033053 A248388

Adjacent sequences: A191287 A191288 A191289 * A191291 A191292 A191293

Keyword

nonn

Author

Clark Kimberling, May 29 2011

Status

approved