1,1

Table of n, a(n) for n=1..63.

Since 13^2+1 = 170 = 2*5*17, the three terms 2, 5, 17 appear in the sequence.

(PARI) row(n)={m=n^2+1; while(m!=1, p=factor(m)[1, 1]; print(p); m=m/p)}

Cf. A027746 A002522

Sequence in context: A107060 A016589 A151572 * A089122 A321577 A268789

Adjacent sequences: A166373 A166374 A166375 * A166377 A166378 A166379

nonn,tabf

Michael B. Porter, Oct 13 2009

approved