1,3

Michael De Vlieger, Table of n, a(n) for n = 1..10000

Index entries for sequences related to primes in arithmetic progressions

a(40) = 1 because in 1600k + 1 at k = 1, 1601 is the smallest prime;

a(61) = 46 because in the 46*46*k + 1 sequence the first prime appears at k = 46; it is 171167.

Table[k = 1; While[! PrimeQ[k (n^2) + 1], k++]; k, {n, 94}] (* Michael De Vlieger, Dec 17 2016 *)

(PARI)

a(n)=k=1; while(!isprime(k*n^2+1), k++); k

vector(100, n, a(n)) \\ Derek Orr, Oct 01 2014

Analogous case is A034693. See also A005574 and A002496.

Sequence in context: A029205 A229340 A072721 * A160598 A107457 A112350

Adjacent sequences: A035089 A035090 A035091 * A035093 A035094 A035095

nonn,easy

Labos Elemer

approved