1,1

Andrew Walker, Table of factors of (n!)^2+1.

Numbers p such that p*q=(A083340(n)!)^2+1, p, q prime, p<q

a(1)=13 because (A083340(1)!)^2+1=518401=13*39877

Cf. A083340, A020549.

Sequence in context: A034270 A155646 A089936 this_sequence A075604 A142297 A131021

Adjacent sequences: A083338 A083339 A083340 this_sequence A083342 A083343 A083344

nonn

Hugo Pfoertner (hugo(AT)pfoertner.org), Apr 25 2003

The 11-th term of the sequence (49-digit factor of the 100 digit number (41!)^2+1 was found with Yuji Kida's multiple polynomial quadratic sieve UBASIC PPMPQS v3.5 in 13 days CPU time on an Intel PIII 550 Mhz.