18365

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 39.at n=37A020378
• Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 15.at n=22A051980
• A recursion triangle sequence: A(n,k) = A(n-1,k-1)+e(n-1,k) where e(n,k)=Sum[(-1)^j Binomial[n + 1, j](k - j)^n, {j, 0, k}].at n=50A157744
• G.f. A(x) satisfies: A(x)^3 = x * A( A(x)^2 + A(x)^3 ).at n=9A272485
• Numbers n such that the decimal digits of n^2 are all prime.at n=14A275971
• Riordan array(1/(1+x), (1-sqrt(1-4*x))/(2*x)).at n=58A278072
• Number of nX3 0..1 arrays with every element equal to 1, 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=5A300541
• Number of nX6 0..1 arrays with every element equal to 1, 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=2A300544
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 1, 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=30A300546
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 1, 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=33A300546
• G.f. A(x) satisfies: 1 = Sum_{n>=0} (-1)^n * x^(n*(n+1)/2) * ((1+x)^n + A(x))^(n+1).at n=9A341341