This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A303874 Number of noncrossing partitions of an n-set up to rotation with all blocks having a prime number of elements. 2
 1, 0, 1, 1, 1, 2, 3, 5, 8, 17, 37, 71, 179, 366, 919, 2069, 5027, 12053, 29098, 71846, 175485, 437438, 1087122, 2723326, 6860525, 17301606, 43957596, 111748571, 285591775, 731432424, 1879009622, 4841510973, 12500324496, 32366232373, 83962263464, 218309244314 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,6 COMMENTS The number of such noncrossing partitions counted distinctly is given by A210737. LINKS Andrew Howroyd, Table of n, a(n) for n = 0..500 PROG (PARI) \\ number of partitions with restricted block sizes NCPartitionsModCyclic(v)={ my(n=#v); my(p=serreverse(x/(1 + sum(k=1, #v, x^k*v[k])) + O(x^2*x^n) )/x); my(vars=variables(p)); my(varpow(r, d)=substvec(r + O(x^(n\d+1)), vars, apply(t->t^d, vars))); my(q=x*deriv(p)/p); my(T=sum(k=1, #v, my(t=v[k]); if(t, x^k*t*sumdiv(k, d, eulerphi(d) * varpow(p, d)^(k/d))/k))); T + 2 + intformal(sum(d=1, n, eulerphi(d)*varpow(q, d))/x) - p } Vec(NCPartitionsModCyclic(vector(40, k, isprime(k)))) CROSSREFS Cf. A054357 (unrestricted), A175954 (1 or 2), A210737, A295198, A303875. Sequence in context: A108054 A123612 A077177 * A145793 A113879 A205303 Adjacent sequences:  A303871 A303872 A303873 * A303875 A303876 A303877 KEYWORD nonn AUTHOR Andrew Howroyd, May 01 2018 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 July 20 15:59 EDT 2019. Contains 325185 sequences. (Running on oeis4.)