OFFSET
0,2
FORMULA
a(n) = 4^n*3*A034176(n-1)/n!, n >= 2, where 3*A034176(n-1)=(4*n-5)(!^4) := product(4*j - 5, j = 2..n);
O.g.f.: A(x) = 2 - (1 - 16*x)^(1/4).
From Peter Bala, Nov 19 2015: (Start)
For n >= 1, a(n) = 1/(sqrt(2)*Pi)*Integrate_{x = 0..16} x^(n-1)*((16 - x)/x)^(1/4).
It appears that sqrt(A(x)) = 1 + 2*x + 10*x^2 + 92*x^3 + 998*x^4 + 11868*x^5 + 149316*x^6 + ... has integer coefficients. (End)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
STATUS
approved