A104995 - OEIS

%I #7 Dec 30 2023 16:44:13

%S 7,13,19,0,31,37,43,97,109,421,463,673,937,1009,2341,3361,3571,6841,

%T 8779,9241,10627,16633,17389,19489,21751,22621,25111,26041,34511,

%U 42181,45943,49921,51481,58549,60271,68113,94351,104729,115831,118801,130873

%N Smallest prime such that n*k(n)^2+n*k(n)+1 is a prime > (n-1)*k(n-1)^2+(n-1)*k(n-1)+1 with k(n)>1 or 0 if n=4 as no prime possible.

%C sequence of k(n) given in A104994

%e 1*2^2+1*2+1=7 prime with k(1)=2

%e 2*2^2+2*2+1=13 prime > 7 with k(2)=2

%e 3*2^2+3*2+1=19 prime > 13 with k(3)=2

%e 5*2^2+5*2+1=31 prime > 19 with k(5)=2

%Y Cf. A104994.

%K nonn

%O 1,1

%A _Pierre CAMI_, Mar 31 2005