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