[seqfan] Set of products of two tetrahedrals

[Richard J. Mathar]

A085780 contains the numbers which are products of two triangular numbers.

Is there any use of adding
0, 1, 4, 10, 16, 20, 35, 40, 56, 80, 84, 100, 120, 140, 165, 200, 220, 224, 286,
336, 350, 364, 400, 455, 480, 560, 660, 680, 700, 816, 840, 880, 969, 1120,
1140, 1144, 1200, 1225, 1330, 1456, 1540, 1650, 1680, 1771, 1820, 1960
and so, defined as numbers that are a product of two tetrahedral numbers?
That would be the A000292 analogue of A000217.

There is also an equivalent to A140089: the numbers which are a nontrivial
product of two tetrahedral numbers, meaning both factors must be >1:
16, 40, 80, 100, 140, 200, 224, 336, 350, 400, 480, 560, 660, 700, 840, 880,
1120, 1144, 1200, 1225, 1456, 1650, 1680, 1820, 1960
from 16=4*4,
40=4*10
80=4*20
100=10*10
140=4*35
200=10*20
224=4*56;
etc.

RJM