OFFSET
0,3
COMMENTS
Note that G(x) such that G(x) = 1 + x*G(x)^4 - x^2/G(x)^14 has negative coefficients.
LINKS
Paul D. Hanna, Table of n, a(n) for n = 0..500
FORMULA
G.f. A(x) satisfies: x^2 = A(x)^13 - A(x)^14 + x*A(x)^17.
EXAMPLE
G.f. A(x) = 1 + x + 3*x^2 + 31*x^3 + 112*x^4 + 1223*x^5 + 5114*x^6 + 66329*x^7 + 316312*x^8 + 4173481*x^9 + 20940941*x^10 + 277101696*x^11 + 1446481076*x^12 + 19319116495*x^13 + 104511172380*x^14 + 1397657888918*x^15 +...
such that A(x) = 1 + x*A(x)^4 - x^2/A(x)^13.
RELATED SERIES.
A(x)^4 = 1 + 4*x + 18*x^2 + 164*x^3 + 911*x^4 + 7844*x^5 + 48792*x^6 + 451668*x^7 + 3073083*x^8 + 29305648*x^9 + 207988496*x^10 +...
1/A(x)^13 = 1 - 13*x + 52*x^2 - 312*x^3 + 2730*x^4 - 17537*x^5 + 135356*x^6 - 1100398*x^7 + 8364707*x^8 - 69113200*x^9 + 559529048*x^10 +...
A(x)^13 = 1 + 13*x + 117*x^2 + 1157*x^3 + 10283*x^4 + 92066*x^5 + 796341*x^6 + 7007286*x^7 + 60731112*x^8 + 535088450*x^9 + 4666522341*x^10 +...
A(x)^14 = 1 + 14*x + 133*x^2 + 1344*x^3 + 12306*x^4 + 112126*x^5 + 989240*x^6 + 8804084*x^7 + 77325101*x^8 + 686378420*x^9 + 6044351516*x^10 +...
A(x)^17 = 1 + 17*x + 187*x^2 + 2023*x^3 + 20060*x^4 + 192899*x^5 + 1796798*x^6 + 16593989*x^7 + 151289970*x^8 + 1377829175*x^9 + 12469684059*x^10 +...
where x^2 = A(x)^13 - A(x)^14 + x*A(x)^17.
PROG
(PARI) {a(n)=local(A=1+x); for(i=1, n, A = 1 + x*A^4 - x^2/A^13 +x*O(x^n)); polcoeff(G=A, n)}
for(n=0, 40, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Nov 23 2017
STATUS
approved