A045924 Numbers n such that prime(n) == -1 (mod n).
1, 2, 3, 4, 10, 70, 72, 182, 440, 1053, 6458, 6461, 6471, 40087, 40089, 251737, 251742, 637320, 637334, 637336, 1617173, 4124466, 10553445, 10553455, 10553569, 10553570, 10553574, 10553576, 10553819, 10553829, 27067100, 27067262, 69709705, 69709719, 69709734, 69709873
Offset: 1
Keywords
Examples
10 is a member because the 10th prime, 29, is congruent to -1 mod 10.
Links
- Giovanni Resta, Table of n, a(n) for n = 1..108
- E. Labos, Graph of prime(n) mod n
Crossrefs
Programs
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Mathematica
NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; p = 1; Do[ If[Mod[p = NextPrim[p], n] == n - 1, Print[n]], {n, 1, 10^9}] (* Robert G. Wilson v, Feb 18 2004 *)
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PARI
isok(n) = Mod(prime(n), n) == -1; \\ Michel Marcus, Jul 24 2018
Extensions
More terms from Patrick De Geest, Nov 15 1999
Terms a(33) and beyond from Giovanni Resta, Feb 23 2020
Comments