A185396 - OEIS

%I #10 Dec 22 2024 23:56:11

%S 2,10,108,235,1201,390050,314766,4035,364384,50411,25955045,5254864,

%T 236558593,16958526,20388056,177544434,492981885,2275400230,256347346,

%U 384902923486,324850200677887

%N Largest number x such that the greatest prime factor of x^2-2 is A038873(n), the n-th prime not congruent to 3 or 5 mod 8.

%C For any prime p, there are finitely many x such that x^2-2 has p as its largest prime factor.

%H Filip Najman, <a href="http://web.math.hr/~fnajman/smooth.pdf">Smooth values of some quadratic polynomials</a>, Glasnik Matematicki Series III 45 (2010), pp. 347-355.

%H Filip Najman, <a href="http://web.math.hr/~fnajman/">Home Page</a> (gives all 537 numbers x such that x^2-2 has no prime factor greater than 199)

%Y Cf. A242488, A379348.

%Y Equivalents for other polynomials: A175607 (x^2 - 1), A145606 (x^2 + x), A185389 (x^2 + 1).

%K nonn

%O 1,1

%A _Charles R Greathouse IV_, Feb 21 2011

%E a(21) added by _Andrew Howroyd_, Dec 22 2024