1516320

Appears in sequences

• Number of (s(0), s(1), ..., s(2n)) such that 0 < s(i) < 8 and |s(i) - s(i-1)| = 1 for i = 1,2,...,2n, s(0) = 1, s(2n) = 3.at n=12A094803
• Number of permutations of length n which avoid the patterns 1234, 2431, 4231.at n=21A116783
• a(n) = ((9+sqrt(9))^n + (9-sqrt(9))^n)/2.at n=6A143079
• Triangle read by rows: T(n, k) = S2[3,1](n, k)*k! with the Sheffer triangle S2[3,1] = (exp(x), exp(3*x) -1) given in A282629.at n=25A284861
• a(n) = Product_{d|n} (d*sigma(d)) where sigma(k) = the sum of the divisors of k (A000203).at n=26A324980
• a(n) = Product_{d|n} lcm(d, sigma(d)) where sigma(k) is the sum of divisors of k (A000203).at n=26A334805