This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A227202 Least prime, q, greater than the previous prime, p, which is a primitive root of p; beginning with 2. 0
 2, 3, 5, 7, 11, 13, 19, 23, 47, 59, 61, 67, 71, 83, 89, 101, 103, 107, 113, 137, 149, 163, 167, 179, 181, 191, 211, 227, 233, 257, 263, 277, 283, 311, 331, 347, 349, 359, 373, 397, 419, 421, 431, 443, 449, 461, 463, 467, 479, 499, 503, 577, 587, 593, 599, 613, 619, 647, 677, 709 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(12^k), k-0… = 2, 3, 7, 23, 101, 277, 823, 1871, 4649, 10369, 23087, 51407, 111779, 240059, 515597, 1100831, 2321563, 4916957, 10370993, 21771443, 45592199, 95294021, 198746747, 413993303, 860461453, …; . a(10^k), k-0… = 2, 59, 1439, 22543, 298943, 3671543, 43346683, 498427109, …, . Conjecture: a(n) < Prime[n*E]. The first prime absent from the sequence is 17, but it will join this sequence at 23. The second prime absent from this sequence is 29, but it will join this sequence by going through 41 and then 47. The third prime absent is 31 which joins at 47. Conjecture: All primes will join this sequence eventually. LINKS EXAMPLE a(7) is not 17 because (13,17) = 1 but is 19 because (13,19) = -1. MATHEMATICA f[s_] := Block[{p = s[[-1]], q = NextPrime[s[[-1]]]}, While[ MultiplicativeOrder[p, q] + 1 != q, q = NextPrime[q]]; Append[s, q]]; Nest[f, {2}, 60] CROSSREFS Cf. A060085. Sequence in context: A030145 A285983 A020588 * A237827 A114111 A155108 Adjacent sequences:  A227199 A227200 A227201 * A227203 A227204 A227205 KEYWORD nonn,easy AUTHOR Robert G. Wilson v, Sep 18 2013 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 October 21 13:24 EDT 2019. Contains 328299 sequences. (Running on oeis4.)