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!)
 A241516 Least positive primitive root g < prime(n) modulo prime(n) which is also a partition number given by A000041, or 0 if such a number g does not exist. 6
 1, 2, 2, 3, 2, 2, 3, 2, 5, 2, 3, 2, 7, 3, 5, 2, 2, 2, 2, 7, 5, 3, 2, 3, 5, 2, 5, 2, 11, 3, 3, 2, 3, 2, 2, 7, 5, 2, 5, 2, 2, 2, 22, 5, 2, 3, 2, 3, 2, 7, 3, 7, 7, 11, 3, 5, 2, 15, 5, 3, 3, 2, 5, 22, 15, 2, 3, 15, 2, 2, 3, 7, 11, 2, 2, 5, 2, 5, 3, 22 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS According to the conjecture in A241504, a(n) should be always positive. LINKS Zhi-Wei Sun, Table of n, a(n) for n = 1..10000 Zhi-Wei Sun, Problems on combinatorial properties of primes, arXiv:1402.6641, 2014. EXAMPLE a(4) = 3 since 3 = A000041(3) is a primitive root modulo prime(4) = 7, but neither 1 = A000041(1) nor 2 = A000041(2) is. MATHEMATICA f[k_]:=PartitionsP[k] dv[n_]:=Divisors[n] Do[Do[If[f[k]>Prime[n]-1, Goto[cc]]; Do[If[Mod[f[k]^(Part[dv[Prime[n]-1], i]), Prime[n]]==1, Goto[aa]], {i, 1, Length[dv[Prime[n]-1]]-1}]; Print[n, " ", PartitionsP[k]]; Goto[bb]; Label[aa]; Continue, {k, 1, Prime[n]-1}]; Label[cc]; Print[Prime[n], " ", 0]; Label[bb]; Continue, {n, 1, 80}] CROSSREFS Cf. A000040, A000041, A237121, A239957, A239963, A241476, A241492, A241504. Sequence in context: A268616 A331506 A002233 * A273458 A159953 A074595 Adjacent sequences:  A241513 A241514 A241515 * A241517 A241518 A241519 KEYWORD nonn AUTHOR Zhi-Wei Sun, Apr 24 2014 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 May 27 17:53 EDT 2020. Contains 334664 sequences. (Running on oeis4.)