Prime and composite terms in Sloane's sequence A056542
Journal of integer sequences, Tome 8 (2005) no. 3
We give the complete factorization of the first fifty terms of the sequence $a_{n} := na_{n-1}+1$ with $a_{1}$ := 0. We searched the terms $a_{n}$ for primes up to $n=1019$ with the result that only the indexes 4, 8, 18, 20 and 70 provide primes. A final section deals with some conjectures on prime terms in this sequence.
@article{JIS_2005__8_3_a1,
author = {M\"uller, Tom},
title = {Prime and composite terms in {Sloane's} sequence {A056542}},
journal = {Journal of integer sequences},
year = {2005},
volume = {8},
number = {3},
zbl = {1096.11507},
language = {en},
url = {http://geodesic.mathdoc.fr/item/JIS_2005__8_3_a1/}
}
Müller, Tom. Prime and composite terms in Sloane's sequence A056542. Journal of integer sequences, Tome 8 (2005) no. 3. http://geodesic.mathdoc.fr/item/JIS_2005__8_3_a1/