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A183234 Ordering of the numbers in tree A183232; complement of A183233. 1
2, 5, 8, 9, 12, 14, 17, 20, 23, 26, 27, 30, 33, 35, 38, 41, 44, 47, 50, 53, 54, 57, 60, 63, 64, 65, 68, 71, 74, 75, 77, 80, 83, 86, 87, 90, 93, 96, 99, 100, 103, 104, 107, 110, 113, 114, 117, 119, 122, 125, 128, 129, 132, 134, 135, 138, 141, 144, 145, 148, 150, 152, 155, 158, 161, 162, 165, 167, 170, 173, 176, 179, 180, 183, 185, 188, 189, 192, 195, 198, 199 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..81.

FORMULA

The monotonic ordering of the numbers in the set S generated by these rules:  2 is in S, and if n is in S, then (n^2+5n+2)/2 and n+Floor(1/2+sqrt(2n+4)) are in S.

MATHEMATICA

nn=200; t={2}; t0=t; While[t=Select[Union[t, (1/2)*(t^2+5t+2), t+Floor[1/2+(2t+4)^(1/2)]], #<=nn&]; t0 !t, t0=t]; t

f[s_List] := Select[ Union@ Join[s, (s^2 + 5 s + 2)/2, s + Floor[1/2 + Sqrt@ (2 s + 4)]], # < 201 &]; NestWhile[f, {2}, UnsameQ, All]

CROSSREFS

Cf. A183232, A183233.

Sequence in context: A161154 A174438 A176061 * A108968 A289628 A047387

Adjacent sequences:  A183231 A183232 A183233 * A183235 A183236 A183237

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jan 02 2011

STATUS

approved

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Last modified September 28 02:29 EDT 2020. Contains 337392 sequences. (Running on oeis4.)