201040

Appears in sequences

• Theta series of D_7 lattice.at n=23A008429
• Number of alternating separable permutations.at n=13A121703
• Table read by rows: T(n, k) = (-1)^(n-k)*F(n, k)/k!, where F are the Faulhaber numbers A354042.at n=31A354043
• a(n) is the smallest positive integer which can be represented as the sum of n distinct nonzero square pyramidal numbers in exactly n ways, or -1 if no such integer exists.at n=35A360218