OFFSET
1,1
COMMENTS
Sequence is finite (see comments at A320884).
LINKS
David A. Corneth, Table of n, a(n) for n = 1..1072
MATHEMATICA
Block[{nn = 9000, nm, m}, nm = Ceiling[(Sqrt[8 nn + 1] - 3)/4]; Union@ Reap[Do[If[a > b > c > 0, Set[m, (a b + 1) (a c + 1)]; If[And[m <= nn, FactorInteger[m][[-1, 1]] <= 7 ], Sow[m]]], {a, nm}, {b, a - 1}, {c, b - 1}]][[2, 1]]] (* Michael De Vlieger, Feb 25 2020, after Jean-François Alcover at A180045 *)
CROSSREFS
KEYWORD
nonn,fini
AUTHOR
Jon E. Schoenfield, Feb 22 2020
STATUS
approved