This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A306351 Number of ways to split an n-cycle into connected subgraphs all having at least 4 vertices. 8
 1, 0, 0, 0, 1, 1, 1, 1, 5, 10, 16, 23, 35, 53, 78, 111, 157, 222, 313, 438, 610, 848, 1178, 1634, 2263, 3131, 4330, 5986, 8272, 11427, 15782, 21794, 30093, 41548, 57359, 79183, 109307, 150887, 208279, 287496, 396838, 547761, 756077, 1043611, 1440488, 1988289 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,9 LINKS Index entries for linear recurrences with constant coefficients, signature (3,-3,1,1,-2,1). FORMULA G.f.: (2*x^9-3*x^8+x^3-3*x^2+3*x-1)/((x^4+x-1)*(x-1)^2). - Alois P. Heinz, Feb 10 2019 EXAMPLE The a(7) = 1 through a(9) = 10 partitions:   {{1234567}}  {{12345678}}    {{123456789}}                {{1234}{5678}}  {{1234}{56789}}                {{1238}{4567}}  {{12345}{6789}}                {{1278}{3456}}  {{12349}{5678}}                {{1678}{2345}}  {{12389}{4567}}                                {{1239}{45678}}                                {{12789}{3456}}                                {{1289}{34567}}                                {{16789}{2345}}                                {{1789}{23456}} MATHEMATICA cycedsprop[n_, k_]:=Union[Sort/@Join@@Table[1+Mod[Range[i, j]-1, n], {i, n}, {j, i+k, n+i-1}]]; spsu[_, {}]:={{}}; spsu[foo_, set:{i_, ___}]:=Join@@Function[s, Prepend[#, s]&/@spsu[Select[foo, Complement[#, Complement[set, s]]=={}&], Complement[set, s]]]/@Cases[foo, {i, ___}]; Table[Length[spsu[cycedsprop[n, 3], Range[n]]], {n, 15}] CROSSREFS Column k = 3 of A323954. Cf. A000325, A005251, A066982, A078012, A323950, A323951, A323953. Sequence in context: A313940 A212455 A052905 * A215341 A194275 A026059 Adjacent sequences:  A306348 A306349 A306350 * A306352 A306353 A306354 KEYWORD nonn,easy AUTHOR Gus Wiseman, Feb 10 2019 EXTENSIONS More terms from Alois P. Heinz, Feb 10 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 December 10 20:48 EST 2019. Contains 329909 sequences. (Running on oeis4.)