205701

Appears in sequences

• a(n) = 1 - (7/6)*n + (2/3)*n^3 + (1/2)*n^4.at n=25A046998
• Sums of squared coefficients in the negative powers of the Catalan function: a(n) = Sum_{k=1..n+1} [x^(n-k+1)] 1/C(x^2)^k, where C(x) is the g.f. of A000108.at n=17A132459
• Numbers k such that the sum of iterations of the alternating sum of divisors function A071324 starting from k is equal to 2*k.at n=7A333263
• Number of nonnegative solutions to (x_1)^2 + (x_2)^2 + ... + (x_10)^2 <= n.at n=24A341405