A078332 - OEIS

A078332

First prime such that p^2 == -1 (mod n), or 0 if no such prime exists.

2, 3, 0, 0, 2, 0, 0, 0, 0, 3, 0, 0, 5, 0, 0, 0, 13, 0, 0, 0, 0, 0, 0, 0, 7, 5, 0, 0, 17, 0, 0, 0, 0, 13, 0, 0, 31, 0, 0, 0, 73, 0, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 23, 0, 0, 0, 0, 17, 0, 0, 11, 0, 0, 0, 47, 0, 0, 0, 0, 0, 0, 0, 173, 31, 0, 0, 0, 0, 0, 0, 0, 73, 0, 0, 13, 0, 0, 0, 233, 0, 0, 0, 0, 0, 0

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..95.

EXAMPLE

a(2)=3 as 3^2 == -1 (mod 2).

PROG

(PARI) for (n=1, 100, f=true; forprime(p=2, 1000, if (p^2%n==(n-1), print1(p", "); f=false; break)); if (f==true, print1(0", ")))

CROSSREFS

Sequence in context: A021817 A167613 A319753 * A097109 A160018 A175099

Adjacent sequences: A078329 A078330 A078331 * A078333 A078334 A078335

KEYWORD

nonn

AUTHOR

Jon Perry, Nov 21 2002

STATUS

approved