A228927 G.f. A(x) satisfies: A(x)^16 = A(x^2)^8 + 16*x.

1, 1, -7, 70, -798, 9737, -124124, 1631041, -21911758, 299371219, -4144898772, 58007463920, -819038646307, 11650826921489, -166786290656152, 2400680788969898, -34719393978035312, 504223005531434252, -7349846348644213981, 107489242662154350550

Offset

0,3

Links

Table of n, a(n) for n=0..19.

Example

 G.f.: A(x) = 1 + x - 7*x^2 + 70*x^3 - 798*x^4 + 9737*x^5 - 124124*x^6 +...
where
A(x)^16 = 1 + 16*x + 8*x^2 - 28*x^4 + 224*x^6 - 2198*x^8 + 23856*x^10 -+...
A(x^2)^8 = 1 + 8*x^2 - 28*x^4 + 224*x^6 - 2198*x^8 + 23856*x^10 -+...

Prog

 (PARI) {a(n)=local(A=1+x); for(i=1, #binary(n), A=(subst(A, x, x^2)^8+16*x+x*O(x^n))^(1/16)); polcoeff(A, n, x)}
for(n=0, 20, print1(a(n), ", "))

Crossrefs

Cf. A228928.

Cf. variants: A107086, A223026.

Sequence in context: A180902 A078246 A268301 * A097184 A002296 A027394

Adjacent sequences: A228924 A228925 A228926 * A228928 A228929 A228930

Keyword

sign

Author

Paul D. Hanna, Sep 08 2013

Status

approved