0,3

Table of n, a(n) for n=0..42.

715 is in the sequence because it is a pentagonal number and the product of its digits 7*1*5=35 is also a pentagonal number.

Cf. A000326.

Sequence in context: A326738 A322927 A333261 * A064019 A134938 A068540

Adjacent sequences: A117707 A117708 A117709 * A117711 A117712 A117713

base,nonn

Luc Stevens (lms022(AT)yahoo.com), Apr 13 2006

approved