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A272633 Discriminator of the primes: Least m > 0 such that (prime(1),...,prime(n)) are all different mod m; a(0) = 0 by convention. 3
0, 1, 2, 4, 6, 7, 7, 13, 13, 13, 19, 19, 19, 23, 23, 23, 31, 31, 31, 33, 37, 37, 43, 43, 47, 49, 53, 53, 53, 55, 61, 63, 67, 73, 73, 75, 75, 79, 83, 83, 89, 89, 91, 91, 97, 103, 103, 109, 113, 113, 115, 117, 119, 121, 121, 121, 121, 121, 139, 139, 141, 141, 151, 153, 157, 157, 159, 167, 169, 169, 175, 181, 181, 183, 187 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

M. F. Hasler and Alois P. Heinz, Table of n, a(n) for n = 0..10000 (first 5001 terms from M. F. Hasler)

Arnold, L. K.; Benkoski, S. J.; and McCabe, B. J.; The discriminator (a simple application of Bertrand's postulate). Amer. Math. Monthly 92 (1985), 275-277.

MAPLE

a:= proc(n) option remember; local m;

      for m from `if`(n=1, 1, a(n-1)) while

        n<>nops({seq(ithprime(i) mod m, i=1..n)})

      do od; m

    end: a(0):=0:

seq(a(n), n=0..80);  # Alois P. Heinz, May 04 2016

MATHEMATICA

a[0]=0; a[n_]:=Block[{m=1}, While[Length@ DeleteDuplicates@ Mod[Prime@ Range@ n, m] != n, m++]; m]; a /@ Range[0, 74] (* Giovanni Resta, May 04 2016 *)

PROG

(PARI) A272633(nMax)={my(S=[], a=1); vector(nMax, n, S=concat(S, prime(n)); while(#Set(S%a)<n, a++); a)}

CROSSREFS

Cf. A016726, A192419, A192420.

Sequence in context: A087777 A030118 A023835 * A240817 A174416 A228728

Adjacent sequences:  A272630 A272631 A272632 * A272634 A272635 A272636

KEYWORD

nonn

AUTHOR

M. F. Hasler, May 04 2016

STATUS

approved

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Last modified November 15 06:21 EST 2019. Contains 329144 sequences. (Running on oeis4.)