OFFSET
2,2
COMMENTS
Each term in the sequence is a sum of tetrahedral numbers.
The underlying triangle mentioned as A143419 was lost and is now restored in A373101. - Georg Fischer, May 23 2024
EXAMPLE
a(5) = 370 = (20 + 165 + 165 + 20) = C(6,3) + C(11,3) + C(11,8) + C(6,3).
MAPLE
seq(add((binomial(n, k)^3 - binomial(n, k))/6, k=1..n-1), n=2..20); # Georg Fischer, May 23 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Gary W. Adamson, Aug 14 2008
EXTENSIONS
Definition changed, a(7) corrected and more terms from Georg Fischer, May 23 2024
STATUS
approved