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A034694 Smallest prime == 1 (mod n). 50
2, 3, 7, 5, 11, 7, 29, 17, 19, 11, 23, 13, 53, 29, 31, 17, 103, 19, 191, 41, 43, 23, 47, 73, 101, 53, 109, 29, 59, 31, 311, 97, 67, 103, 71, 37, 149, 191, 79, 41, 83, 43, 173, 89, 181, 47, 283, 97, 197, 101, 103, 53, 107, 109, 331, 113, 229, 59, 709, 61, 367, 311 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Thangadurai and Vatwani prove that a(n) <= 2^(phi(n)+1)-1. - T. D. Noe, Oct 12 2011

REFERENCES

S. R. Finch, Mathematical Constants, Cambridge, 2003, pp. 127-130.

Graham, D. (1981): On Linnik's Constant. Acta Arithm.,39:163-179.

Niven I. and Powell, B. (1976): Primes in Certain Arithmetic Progressions. Amer. Math. Monthly,83:467-489.

Ribenboim, P. (1989):The Book of Prime Number Records. Chapter 4,IV.B.: The Smallest Prime In Arithmetic Progressions, pp. 217-223.

R. Thangadurai and A. Vatwani, The least prime congruent to one modulo n, Amer. Math. Monthly, Vol. 118, 2011, p. 737-742.

LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000

S. R. Finch, More about Linnik's Constant

EXAMPLE

If n = 7, the smallest prime in the sequence 8,15,22,29,... is 29, so a(7) = 29.

MATHEMATICA

f[n_] := Block[{k = 1}, If[n == 1, 2, While[Mod[Prime@k, n] != 1, k++ ]; Prime@k]]; Array[f, 64] (from Robert G. Wilson v (rgwv(at)rgwv.com), Jul 08 2006)

PROG

(PARI) a(n)=if(n<0, 0, s=1; while((prime(s)-1)%n>0, s++); prime(s))

CROSSREFS

Cf. A034693, A034694, A034780, A034782, A034783, A034784, A034785, A034846, A034847, A034848, A034849.

Cf. A085420. Records: A120856, A120857.

Sequence in context: A085102 A087572 A085107 * A050921 A087386 A110359

Adjacent sequences:  A034691 A034692 A034693 * A034695 A034696 A034697

KEYWORD

nonn,nice,easy

AUTHOR

Labos Elemer (LABOS(AT)ana.sote.hu), David W. Wilson (davidwwilson(AT)comcast.net), Spring 1998

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Last modified February 14 18:47 EST 2012. Contains 205663 sequences.