OFFSET
1,1
LINKS
Eric Weisstein's World of Mathematics, Tetrahedral Number
EXAMPLE
a(3) = 260 = 1 + 4 + 35 + 220 = 1 + 10 + 84 + 165 = 4 + 35 + 56 + 165.
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jul 20 2024
STATUS
approved