75706

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 61.at n=1A031649
• If n = 0 or 1 then a(n) = 1; if n = 2, 3 or 4 then a(n) = 0; otherwise a(n) = (n+1)*a(n-1)-(n-2)*a(n-2)-(n-5)*a(n-3)+(n-3)*a(n-4).at n=10A085372
• Number of numbers expressible as b(1)*b(2)*...*b(n) with 1 <= b(i) <= i for each i.at n=14A345882