106400

Appears in sequences

• Variance of time for a random walk starting at 0 to reach one of the boundaries at +n or -n for the first time.at n=20A072819
• a(n) = 6 + floor((1 + Sum_{j=1..n-1} a(j))/3).at n=34A120152
• Generalized q-Stirling 2nd numbers (see A022166):q=3;m=2; t1(n, k, q_) = (1/(q - 1)^k)*Sum[(-1)^(k - j)*Binomial[k + n, k -j]*q-Binomial[j + n, j, q - 1], {j, 0, k}].at n=13A156824
• Transform of the finite sequence (1, 0, -1) by the T_{1,1} transformation (see link).at n=13A159329
• Easter occurrences on March 22, March 23, ..., April 25 during a 5,700,000-year Gregorian Easter cycle.at n=32A224110
• Lesser of amicable pair m < n defined by t(n) = m and t(m) = n where t(n) = psi(n) - n and psi(n) = A001615(n) is the Dedekind psi function.at n=36A323329
• G.f.: Sum_{n>=0} x^n * (x^n + i)^n / (1 + i*x^(n+1))^(n+1), where i^2 = -1.at n=81A323675
• Triangle read by rows: T(n, k) = qStirling2(n, k, q) for q = 3, with 0 <= k <= n.at n=24A333143
• Maximum number of copies of a 1234 permutation pattern in an alternating (or zig-zag) permutation of length n + 5.at n=37A338429