172012

Appears in sequences

• Number of nXnXn triangular nonnegative integer arrays, symmetric under 120 degree rotation, with all sums of an element and its neighbors <= 8.at n=7A166203
• Number of 7X7X7 triangular nonnegative integer arrays, symmetric under 120 degree rotation, with all sums of an element and its neighbors <= n.at n=8A166215
• a(n) = 42*2^n - 20.at n=12A305064