A143420 Row sums of triangle A373101.

1, 8, 55, 370, 2520, 17472, 123151, 880070, 6360706, 46402312, 341153384, 2524722928, 18789734496, 140521154048, 1055383259791, 7956220907758, 60179579570382, 456545145078408, 3472804505717170

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

Links

Table of n, a(n) for n=2..20.

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

Cf. A108958 (row sums of A143418), A373101.

Sequence in context: A110184 A013698 A154245 * A075734 A033890 A010924

Adjacent sequences: A143417 A143418 A143419 * A143421 A143422 A143423

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