OFFSET
1,1
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Andrzej Rotkiewicz, On pyramidal numbers of order 4, Elemente der Mathematik, Vol. 28 (1973), pp. 14-16.
Wikipedia, Schinzel's Hypothesis H.
MATHEMATICA
p[n_]:=n(n+1)(2n+1)/6; Select[p[Range[3, 10^6]], PowerMod[2, (#-1), #] == 1 &]
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Oct 13 2017
STATUS
approved