30436

Appears in sequences

• a(1) = 2; a(n+1) = a(n)-th nonprime, where nonprimes begin at 1.at n=43A025003
• Triangle read by rows: T(n,k) = coefficient of x^k in the polynomial p[n,x] defined by p[0,x]=1, p[1,x]=1+x and p[n,x]=(1+x)(2-x)(3-x)...(n-x) for n >= 2 (0 <= k <= n).at n=39A123361
• Number of (n+1)X(n+1) -11..11 symmetric matrices with every 2X2 subblock having sum zero and two or three distinct values.at n=6A211713
• Numbers n such that the decimal number concat(6,n) is a square.at n=38A273361
• Expansion of g.f. A(x) satisfying 1 - Sum_{n>=1} Product_{k=1..n} (x^(2*k-1) - 3*A(x)) = Product_{k>=1} (1 - x^(2*k)) * (1 + x^k - 3*A(x))^2 / (1 + x^(2*k) - 3*A(x))^2.at n=5A370346