90021

Appears in sequences

• Coefficient of x^4 in expansion of (1+x+x^2)^n.at n=35A005712
• a(n) = ceiling(A107293(n)/2).at n=38A173693
• Number of zero-sum -n..n arrays of 6 elements with first and second differences also in -n..n.at n=8A201877
• a(n) = floor( exp(gamma) k log log k ) - sigma(k), where gamma is Euler's constant (A001620) and sigma(k) is sum of divisors of k (A000203), the n-th colossally abundant number (A004490).at n=9A279702
• a(n) = Trinomial(2*n+1, 4) = (1/6)*n*(2*n + 1)*(2*n^2 + 9*n + 1), n >= 0.at n=18A302709
• a(n-5) is the number of nonempty subsets of {1,2,...,n} such that the difference of successive elements is at least 5.at n=34A330910