The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A324766 Matula-Goebel numbers of recursively anti-transitive rooted trees. 5
 1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 16, 17, 19, 20, 21, 22, 23, 25, 27, 29, 31, 32, 33, 34, 35, 40, 44, 46, 49, 50, 51, 53, 57, 59, 62, 63, 64, 67, 68, 71, 73, 77, 79, 80, 81, 83, 85, 87, 88, 92, 93, 95, 97, 99, 100, 103, 109, 115, 118, 121, 124, 125, 127, 128 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The complement is {6, 12, 13, 14, 15, 18, 24, 26, 28, 30, 36, ...}. An unlabeled rooted tree is recursively anti-transitive if no branch of a branch of a terminal subtree is a branch of the same subtree. LINKS EXAMPLE The sequence of recursively anti-transitive rooted trees together with their Matula-Goebel numbers begins:    1: o    2: (o)    3: ((o))    4: (oo)    5: (((o)))    7: ((oo))    8: (ooo)    9: ((o)(o))   10: (o((o)))   11: ((((o))))   16: (oooo)   17: (((oo)))   19: ((ooo))   20: (oo((o)))   21: ((o)(oo))   22: (o(((o))))   23: (((o)(o)))   25: (((o))((o)))   27: ((o)(o)(o))   29: ((o((o))))   31: (((((o)))))   32: (ooooo)   33: ((o)(((o))))   34: (o((oo)))   35: (((o))(oo))   40: (ooo((o)))   44: (oo(((o))))   46: (o((o)(o)))   49: ((oo)(oo))   50: (o((o))((o))) MATHEMATICA primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]]; totantiQ[n_]:=And[Intersection[Union@@primeMS/@primeMS[n], primeMS[n]]=={}, And@@totantiQ/@primeMS[n]]; Select[Range[100], totantiQ] CROSSREFS Cf. A007097, A000081, A290689, A303431, A304360, A306844, A316502, A318186. Cf. A324695, A324751, A324756, A324758, A324765, A324767, A324769, A324838, A324841, A324844. Sequence in context: A004743 A114994 A137706 * A039224 A161508 A039264 Adjacent sequences:  A324763 A324764 A324765 * A324767 A324768 A324769 KEYWORD nonn AUTHOR Gus Wiseman, Mar 17 2019 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 5 03:52 EDT 2020. Contains 333238 sequences. (Running on oeis4.)