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A107095 G.f. satisfies: A(A(x)) = (1+x)^2*A(x). 2
0, 1, 2, -3, 18, -150, 1518, -17541, 223782, -3087948, 45470022, -707810715, 11569008816, -197540043324, 3509923686678, -64697804055675, 1234127209128306, -24312707152663590, 493834352052852738, -10327320248199824889, 222086739445484152590 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

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

FORMULA

G.f. A(x) = G(x)^2/x where G(x) is g.f. of A107096.

a(n)=T(n,1), T(n,m)=sum(i=1..n-m, binomial(2*m,i)*T(n-i,m))-sum(k=m+1..n-1, T(n,k)*T(k,m)), n>m, T(n,n)=1. [Vladimir Kruchinin May 03 2012]

PROG

(PARI) {a(n)=local(A, B, F); if(n<1, 0, F=x+2*x^2+x*O(x^n); A=F; for(j=0, n, for(i=0, j, B=serreverse(A); A=(A+subst(B, x, A*(1+x)^2))/2); A=round(A)); polcoeff(A, n, x))}

(Maxima) T(n, m):=if n=m then 1 else sum(binomial(2*m, i)*T(n-i, m), i, 1, n-m)-sum(T(n, k)*T(k, m), k, m+1, n-1); makelist(T(n, 1), n, 1, 10); [Vladimir Kruchinin May 03 2012]

CROSSREFS

Cf. A107096.

Sequence in context: A184719 A076016 A226961 * A102939 A073983 A230602

Adjacent sequences:  A107092 A107093 A107094 * A107096 A107097 A107098

KEYWORD

sign

AUTHOR

Paul D. Hanna, May 12 2005

STATUS

approved

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Last modified July 4 03:54 EDT 2022. Contains 355063 sequences. (Running on oeis4.)