1593835520

Appears in sequences

• a(1) = 4; a(n) = smallest composite number greater than the sum of all previous terms.at n=29A070232
• Expansion of ((1-x)*(3*x^2-3*x+1))/(1-2*x)^3.at n=25A190050
• a(n) = Sum_{k=0..2n}(k!*(2n - k)!)/(floor(k/2)!*floor((2n - k)/2)!)^2.at n=13A327999
• a(n) = Sum_{k=0..n}(k!*(n - k)!)/(floor(k/2)!*floor((n - k)/2)!)^2.at n=26A328000
• a(n) is the least k such that A161606(k) = n or a(n) = -1 if no such k exists.at n=26A385677
• Smallest integer k whose sum of its distinct prime factors and bigomega(k) both equal n; or -1 if no such integer exists.at n=24A386605