A185396 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.

2, 10, 108, 235, 1201, 390050, 314766, 4035, 364384, 50411, 25955045, 5254864, 236558593, 16958526, 20388056, 177544434, 492981885, 2275400230, 256347346, 384902923486, 324850200677887

Offset

1,1

Comments

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

Links

Table of n, a(n) for n=1..21.

Filip Najman, Smooth values of some quadratic polynomials, Glasnik Matematicki Series III 45 (2010), pp. 347-355.

Filip Najman, Home Page (gives all 537 numbers x such that x^2-2 has no prime factor greater than 199)

Crossrefs

Cf. A242488, A379348.

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

Sequence in context: A127728 A306064 A355210 * A003222 A262145 A355209

Adjacent sequences: A185393 A185394 A185395 * A185397 A185398 A185399

Keyword

nonn,changed

Author

Charles R Greathouse IV, Feb 21 2011

Extensions

a(21) added by Andrew Howroyd, Dec 22 2024

Status

approved