A186969 - OEIS

A186969

Smallest prime p such that k*p + k + 1 is prime for k=1..n.

3, 5, 5, 4259, 25409, 25409, 512819, 512819, 17733438029, 1095010766849, 766405913232959

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

EXAMPLE

n=1: p=3 and p+2=5 both primes

n=2,3: p=5, p+2=7, 2*p+3=13, and 3*p+4=19 all four primes

n=4: p=4259, p+2=4261, 2*p+3=8521, 3*p+4=12781, and 4*p+5=17041 all five primes.

CROSSREFS

KEYWORD

nonn,more,hard

AUTHOR

Zak Seidov, Mar 01 2011

EXTENSIONS

a(10), a(11) from Max Alekseyev, Mar 10 2011

STATUS

approved