A302107 G.f. A(x) satisfies: [x^(n+1)] A(x)^(n^2) / (x*A(x)^n)' = 0 for n>=0.

1, 1, 1, 1, 7, 211, 8411, 412301, 24894581, 1832290133, 162840289853, 17318483860823, 2184687906940713, 323935018037153709, 55939700211256251813, 11149440249347239643775, 2542901827027280314993359, 658411118385997264277976111, 192135231563520713206597464479, 62778202074038700301319695876973, 22831139565407893815484402030333403

Offset

0,5

Comments

Compare to: [x^(n-1)] (x*F(x)^n)' / F(x)^(n^2) = 0 for n>0 holds when F(0) = 1.

Links

Table of n, a(n) for n=0..20.

Formula

G.f. A(x) satisfies: [x^(n+1)] A(x)^(n^2-n+1) / (A(x) + n*x*A'(x)) = 0 for n>=0.

Example

G.f.: A(x) = 1 + x + x^2 + x^3 + 7*x^4 + 211*x^5 + 8411*x^6 + 412301*x^7 + 24894581*x^8 + 1832290133*x^9 + 162840289853*x^10 + ...
ILLUSTRATION OF DEFINITION.
The table of coefficients of x^k in  A(x)^(n^2) / (x*A(x)^n)' begins:
n=0: [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ...];
n=1: [1, -1, 0, 0, -24, -972, -47184, -2729850, -190252260, ...];
n=2: [1, 0, 1, 0, -35, -1536, -78051, -4655400, -331711815, ...];
n=3: [1, 3, 9, 17, 0, -1674, -94734, -5917068, -433817613, ...];
n=4: [1, 8, 42, 160, 497, 0, -90536, -6434272, -496083426, ...];
n=5: [1, 15, 130, 810, 4075, 16929, 0, -5638950, -504633465, ...];
n=6: [1, 24, 315, 2920, 21396, 132264, 707500, 0, -412691760, ...];
n=7: [1, 35, 651, 8435, 85225, 716457, 5290089, 35515563, 0, ...]; ...
illustrating that the coefficient of x^(n+1) in A(x)^(n^2) / (x*A(x)^n)' equals 0 for n>=0.

Prog

(PARI) {a(n) = my(A=[1, 1]); for(i=1, n, A = concat(A, 0); A[#A] = Vec( Ser(A)^((#A-2)^2)/(x*Ser(A)^(#A-2))' )[#A]/if(#A==2, 1, 2*(#A-2)) ); A[n+1]}
for(n=0, 20, print1(a(n), ", "))

Crossrefs

Cf. A300995.

Sequence in context: A065819 A241649 A256288 * A061028 A012862 A045760

Adjacent sequences: A302104 A302105 A302106 * A302108 A302109 A302110

Keyword

nonn

Author

Paul D. Hanna, Apr 05 2018

Status

approved