A092581 - OEIS

A092581

a(n) is the least prime such that a(n-1) is a quadratic non-residue of a(n).

2, 3, 5, 7, 11, 13, 19, 23, 31, 37, 43, 47, 59, 61, 67, 71, 79, 83, 89, 101, 103, 107, 109, 127, 131, 137, 149, 151, 157, 163, 167, 179, 181, 191, 199, 227, 229, 239, 251, 257, 263, 271, 277, 283, 307, 311, 331, 347, 349, 359, 367, 373, 379, 383, 409, 431, 439

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OFFSET

1,1

REFERENCES

Paulo Ribenboim, "The Little Book of Big Primes", Springer-Verlag, 1991, p. 28.

LINKS

T. D. Noe, Table of n, a(n) for n=1..1000

FORMULA

"If p>2 does not divide a and if there exists an integer b such that a is congruent to b^2 (mod p), then a is called a quadratic residue modulo p; otherwise, it is a nonquadratic residue modulo p". (p. 28, Ribenboim)

MATHEMATICA

first Needs[ "NumberTheory`NumberTheoryFunctions`" ] then f[n_] := Block[{k = PrimePi[n] + 1}, While[ JacobiSymbol[n, Prime[k]] == 1, k++ ]; Prime[k]]; NestList[f, 2, 56] (* Robert G. Wilson v, Mar 16 2004 *)

CROSSREFS

Cf. A034794.

Sequence in context: A078334 A108696 A215642 * A362527 A130807 A338577

Adjacent sequences: A092578 A092579 A092580 * A092582 A092583 A092584

KEYWORD

nonn

AUTHOR

Gary W. Adamson, Feb 29 2004

EXTENSIONS

More terms from Robert G. Wilson v, Mar 16 2004

a(17) corrected by T. D. Noe, Aug 28 2007

STATUS

approved