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

Author

Gary W. Adamson, Aug 14 2008

Keywords

• nonn
• easy

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

Examples

			a(5) = 370 = (20 + 165 + 165 + 20) = C(6,3) + C(11,3) + C(11,8) + C(6,3).
		

Crossrefs

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

Programs

Maple

seq(add((binomial(n,k)^3 - binomial(n,k))/6,k=1..n-1),n=2..20); # Georg Fischer, May 23 2024

Extensions

Definition changed, a(7) corrected and more terms from Georg Fischer, May 23 2024