cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-9 of 9 results.

A120971 G.f. A(x) satisfies A(x) = 1 + x*A(x)^2 * A( x*A(x)^2 )^2.

Original entry on oeis.org

1, 1, 4, 26, 218, 2151, 23854, 289555, 3783568, 52624689, 772928988, 11918181144, 192074926618, 3224153299106, 56213565222834, 1015694652332437, 18982833869517376, 366384235565593176, 7292660345274942402
Offset: 0

Views

Author

Paul D. Hanna, Jul 20 2006

Keywords

Examples

			G.f.: A(x) = 1 + x + 4*x^2 + 26*x^3 + 218*x^4 + 2151*x^5 + 23854*x^6 +...
From _Paul D. Hanna_, Apr 16 2007: G.f. A(x) is the unique solution to variable A in the infinite system of simultaneous equations:
A = 1 + x*B^2;
B = A*(1 + x*C^2);
C = B*(1 + x*D^2);
D = C*(1 + x*E^2);
E = D*(1 + x*F^2); ...
The above series begin:
B(x) = 1 + 2*x + 11*x^2 + 87*x^3 + 841*x^4 + 9288*x^5 + 113166*x^6 +...
C(x) = 1 + 3*x + 21*x^2 + 198*x^3 + 2204*x^4 + 27431*x^5 + 371102*x^6 +...
D(x) = 1 + 4*x + 34*x^2 + 374*x^3 + 4747*x^4 + 66350*x^5 + 996943*x^6 +...
E(x) = 1 + 5*x + 50*x^2 + 630*x^3 + 9015*x^4 + 140510*x^5 + 2334895*x^6 +...
F(x) = 1 + 6*x + 69*x^2 + 981*x^3 + 15658*x^4 + 270016*x^5 + 4933294*x^6 +...
		

Crossrefs

Programs

  • Mathematica
    m = 19; A[] = 0; Do[A[x] = 1 + x A[x]^2 A[x A[x]^2]^2 + O[x]^m, {m}];
    CoefficientList[A[x], x] (* Jean-François Alcover, Nov 07 2019 *)
  • PARI
    {a(n)=local(A,G=[1,1]);for(i=1,n,G=concat(G,0); G[ #G]=-Vec(subst(Ser(G),x,x/Ser(G)^2))[ #G]); A=Vec(((Ser(G)-1)/x)^(1/2));A[n+1]}
    
  • PARI
    a(n, k=1) = if(k==0, 0^n, k*sum(j=0, n, binomial(2*n+k, j)/(2*n+k)*a(n-j, 2*j))); \\ Seiichi Manyama, Mar 01 2025

Formula

G.f. A(x) satisfies:
(1) A(x) = G(G(x)-1),
(2) A(G(x)-1) = G(A(x)-1),
(3) A(x) = G(x*A(x)^2),
(4) A(x/G(x)^2) = G(x),
where G(x) is the g.f. of A120970 and satisfies G(x/G(x)^2) = 1 + x.
G.f. A(x) = F(x,1) where F(x,n) satisfies: F(x,n) = F(x,n-1)*(1 + x*F(x,n+1)^2) for n>0 with F(x,0)=1. - Paul D. Hanna, Apr 16 2007
Let B(x) = Sum_{n>=0} a(n)*x^(2*n+1), then B( x/(1+B(x)^2) ) = x. - Paul D. Hanna, Oct 30 2013
From Seiichi Manyama, Mar 01 2025: (Start)
Let a(n,k) = [x^n] A(x)^k.
a(n,0) = 0^n; a(n,k) = k * Sum_{j=0..n} binomial(2*n+k,j)/(2*n+k) * a(n-j,2*j). (End)

A120972 G.f. A(x) satisfies A(x/A(x)^3) = 1 + x ; thus A(x) = 1 + series_reversion(x/A(x)^3).

Original entry on oeis.org

1, 1, 3, 21, 217, 2814, 42510, 718647, 13270944, 263532276, 5567092665, 124143735663, 2905528740060, 71058906460091, 1809695198254281, 47861102278428198, 1311488806252697283, 37164457324943708739, 1087356593493807164289, 32801308084353988297404
Offset: 0

Views

Author

Paul D. Hanna, Jul 20 2006

Keywords

Comments

More generally, if g.f. A(x) satisfies: A(x/A(x)^k) = 1 + x*A(x)^m, then
A(x) = 1 + x*G(x)^(m+k) where G(x) = A(x*G(x)^k) and G(x/A(x)^k) = A(x);
thus a(n) = [x^(n-1)] ((m+k)/(m+k*n))*A(x)^(m+k*n) for n>=1 with a(0)=1.

Examples

			G.f.: A(x) = 1 + x + 3*x^2 + 21*x^3 + 217*x^4 + 2814*x^5 + 42510*x^6 +...
Related expansions.
A(x)^3 = 1 + 3*x + 12*x^2 + 82*x^3 + 813*x^4 + 10212*x^5 + 150699*x^6 +...
A(A(x)-1) = 1 + x + 6*x^2 + 60*x^3 + 776*x^4 + 11802*x^5 + 201465*x^6 +...
A(A(x)-1)^3 = 1 + 3*x + 21*x^2 + 217*x^3 + 2814*x^4 + 42510*x^5 +...
x/A(x)^3 = x - 3*x^2 - 3*x^3 - 37*x^4 - 420*x^5 - 5823*x^6 -...
Series_Reversion(x/A(x)^3) = x + 3*x^2 + 21*x^3 + 217*x^4 + 2814*x^5 + 42510*x^6 +...
To illustrate the formula a(n) = [x^(n-1)] 3*A(x)^(3*n)/(3*n),
form a table of coefficients in A(x)^(3*n) as follows:
  A^3:  [(1), 3,  12,   82,    813,   10212,   150699,   2503233, ...];
  A^6:  [ 1, (6), 33,  236,   2262,   27270,   388906,   6289080, ...];
  A^9:  [ 1,  9, (63), 489,   4671,   54684,   756012,  11904813, ...];
  A^12: [ 1, 12, 102, (868),  8445,   97260,  1310040,  20112516, ...];
  A^15: [ 1, 15, 150, 1400, (14070), 161343,  2130505,  31961175, ...];
  A^18: [ 1, 18, 207, 2112,  22113, (255060), 3324003,  48876264, ...];
  A^21: [ 1, 21, 273, 3031,  33222,  388563, (5030529), 72769014, ...]; ...
in which the main diagonal forms the initial terms of this sequence:
[3/3*(1), 3/6*(6), 3/9*(63), 3/12*(868), 3/15*(14070), 3/18*(255060), ...].
		

Crossrefs

Programs

  • Mathematica
    terms = 18; A[] = 1; Do[A[x] = 1 + x*A[A[x] - 1]^3 + O[x]^j // Normal, {j, terms}]; CoefficientList[A[x], x] (* Jean-François Alcover, Jan 15 2018 *)
  • PARI
    {a(n)=local(A=[1,1]);for(i=2,n,A=concat(A,0); A[ #A]=-Vec(subst(Ser(A),x,x/Ser(A)^3))[ #A]);A[n+1]}
    
  • PARI
    {a(n)=local(A=1+x+x*O(x^n));for(i=1,n,A=1+x*subst(A^3,x,A-1+x*O(x^n)));polcoeff(A,n)}
    
  • PARI
    /* This sequence is generated when k=3, m=0: A(x/A(x)^k) = 1 + x*A(x)^m */
    {a(n, k=3, m=0)=local(A=sum(i=0, n-1, a(i, k, m)*x^i)); if(n==0, 1, polcoeff((m+k)/(m+k*n)*A^(m+k*n), n-1))}
    for(n=0,25,print1(a(n),", "))
    
  • PARI
    b(n, k) = if(k==0, 0^n, k*sum(j=0, n, binomial(3*n+k, j)/(3*n+k)*b(n-j, 3*j)));
    a(n) = if(n==0, 1, b(n-1, 3)); \\ Seiichi Manyama, Jun 04 2025

Formula

G.f. satisfies: A(x) = 1 + x*A(A(x) - 1)^3.
a(n) = [x^(n-1)] A(x)^(3*n)/n for n>=1 with a(0)=1; i.e., a(n) equals the coefficient of x^(n-1) in A(x)^(3*n)/n for n>=1 (see comment).
Let B(x) be the g.f. of A120973, then B(x) and g.f. A(x) are related by:
(a) B(x) = A(A(x)-1),
(b) B(x) = A(x*B(x)^3),
(c) A(x) = B(x/A(x)^3),
(d) A(x) = 1 + x*B(x)^3,
(e) B(x) = 1 + x*B(x)^3*B(A(x)-1)^3,
(f) A(B(x)-1) = B(A(x)-1) = B(x*B(x)^3).
From Seiichi Manyama, Jun 04 2025: (Start)
Let b(n,k) = [x^n] B(x)^k, where B(x) is the g.f. of A120973.
b(n,0) = 0^n; b(n,k) = k * Sum_{j=0..n} binomial(3*n+k,j)/(3*n+k) * b(n-j,3*j).
a(n) = b(n-1,3) for n > 0. (End)

A120974 G.f. A(x) satisfies A(x/A(x)^4) = 1 + x; thus A(x) = 1 + series_reversion(x/A(x)^4).

Original entry on oeis.org

1, 1, 4, 38, 532, 9329, 190312, 4340296, 108043128, 2890318936, 82209697588, 2467155342740, 77676395612884, 2554497746708964, 87449858261161216, 3107829518797739032, 114399270654847628768, 4353537522757357068296, 171010040645759712226048
Offset: 0

Views

Author

Paul D. Hanna, Jul 20 2006

Keywords

Crossrefs

Programs

  • Maple
    A:= x -> 1:
    for m from 1 to 30 do
      Ap:= unapply(A(x)+c*x^m,x);
      S:= series(Ap(x/Ap(x)^4)-1-x, x, m+1);
      cs:= solve(convert(S,polynom),c);
      A:= subs(c=cs, eval(Ap));
    od:
    seq(coeff(A(x),x,m),m=0..30);# Robert Israel, Oct 25 2019
  • Mathematica
    nmax = 17; sol = {a[0] -> 1};
    Do[A[x_] = Sum[a[k] x^k, {k, 0, n}] /. sol; eq = CoefficientList[ A[x/A[x]^4] - 1 - x + O[x]^(n + 1), x] == 0 /. sol; sol = sol ~Join~ Solve[eq][[1]], {n, 1, nmax}];
    sol /. Rule -> Set;
    a /@ Range[0, nmax] (* Jean-François Alcover, Nov 02 2019 *)
  • PARI
    {a(n)=local(A=[1,1]);for(i=2,n,A=concat(A,0); A[ #A]=-Vec(subst(Ser(A),x,x/Ser(A)^4))[ #A]);A[n+1]}
    
  • PARI
    b(n, k) = if(k==0, 0^n, k*sum(j=0, n, binomial(4*n+k, j)/(4*n+k)*b(n-j, 4*j)));
    a(n) = if(n==0, 1, b(n-1, 4)); \\ Seiichi Manyama, Jun 04 2025

Formula

G.f. satisfies: A(x) = 1 + x*B(x)^4 = 1 + (1 + x*C(x)^4 )^4 where B(x) and C(x) satisfy: C(x) = B(x)*B(A(x)-1), B(x) = A(A(x)-1), B(A(x)-1) = A(B(x)-1), B(x/A(x)^4) = A(x), B(x) = A(x*B(x)^4) and B(x) is g.f. of A120975.
From Seiichi Manyama, Jun 04 2025: (Start)
Let b(n,k) = [x^n] B(x)^k, where B(x) is the g.f. of A120975.
b(n,0) = 0^n; b(n,k) = k * Sum_{j=0..n} binomial(4*n+k,j)/(4*n+k) * b(n-j,4*j).
a(n) = b(n-1,4) for n > 0. (End)

A120976 G.f. A(x) satisfies A(x/A(x)^5) = 1 + x ; thus A(x) = 1 + series_reversion(x/A(x)^5).

Original entry on oeis.org

1, 1, 5, 60, 1060, 23430, 602001, 17281760, 541258390, 18210836060, 651246905140, 24566101401035, 971933892729980, 40156993344526860, 1726753293393763625, 77065076699967844390, 3561820706538663354320, 170162336673835615653925, 8389644485709060522744640
Offset: 0

Views

Author

Paul D. Hanna, Jul 20 2006

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=local(A=[1,1]);for(i=2,n,A=concat(A,0); A[ #A]=-Vec(subst(Ser(A),x,x/Ser(A)^5))[ #A]);A[n+1]}
    
  • PARI
    b(n, k) = if(k==0, 0^n, k*sum(j=0, n, binomial(5*n+k, j)/(5*n+k)*b(n-j, 5*j)));
    a(n) = if(n==0, 1, b(n-1, 5)); \\ Seiichi Manyama, Jun 04 2025

Formula

G.f. satisfies: A(x) = 1 + x*B(x)^5 = 1 + (1 + x*C(x)^5 )^5 where B(x) and C(x) satisfy: C(x) = B(x)*B(A(x)-1), B(x) = A(A(x)-1), B(A(x)-1) = A(B(x)-1), B(x/A(x)^5) = A(x), B(x) = A(x*B(x)^5) and B(x) is g.f. of A120977.
From Seiichi Manyama, Jun 04 2025: (Start)
Let b(n,k) = [x^n] B(x)^k, where B(x) is the g.f. of A120977.
b(n,0) = 0^n; b(n,k) = k * Sum_{j=0..n} binomial(5*n+k,j)/(5*n+k) * b(n-j,5*j).
a(n) = b(n-1,5) for n > 0. (End)

A120955 G.f. A(x) satisfies: Series_Reversion( x/A(x) ) / x = 2*A(x) - (1+x).

Original entry on oeis.org

1, 1, 1, 4, 25, 206, 2060, 23920, 314065, 4582300, 73393490, 1278859176, 24073541260, 486806278752, 10525038917720, 242318610557760, 5919811842140945, 152974724047702626, 4169576527021400852
Offset: 0

Views

Author

Paul D. Hanna, Jul 19 2006

Keywords

Comments

The g.f. for A120956 = Series_Reversion( x/A(x) ) / x = 2*A(x) - (1+x), where A(x) is the g.f. of this sequence.

Examples

			A(x) = 1 + x + x^2 + 4*x^3 + 25*x^4 + 206*x^5 + 2060*x^6 +...
The g.f. of A120956 is:
series_reversion(x/A(x))/x = 1 + x + 2*x^2 + 8*x^3 + 50*x^4 + 412*x^5 +...
Compare terms to see that A120956(n) = 2*a(n) for n>=2.
The g.f. satisfies the series:
A(x) = 1+x + x*d/dx (A(x)-1)^2/2! + x^2*d^2/dx^2 (A(x)-1)^3/3! + x^3*d^3/dx^3 (A(x)-1)^4/4! + x^4*d^4/dx^4 (A(x)-1)^5/5! +...
		

Crossrefs

Cf. A120956, A120970 (variant), A249933.

Programs

  • PARI
    a(n)=local(A=[1,1]);for(i=1,n,A=concat(A,t); A[ #A]=subst(Vec(serreverse(x/Ser(A)))[ #A],t,0));A[n+1]
    for(n=0, 25, print1(a(n), ", "))
    
  • PARI
    Dx(n, F)=local(D=F); for(i=1, n, D=deriv(D)); D
    {a(n)=local(A=1+x*O(x^n)); for(i=1, n, A=1+x+sum(m=1, n, x^m*Dx(m, (A-1+x*O(x^n))^(m+1)/(m+1)!) )); polcoeff(A, n)}
    for(n=0, 25, print1(a(n), ", ")) \\ Paul D. Hanna, Dec 27 2012

Formula

G.f. A(x) satisfies:
(1) A( x*(2*A(x) - 1-x) ) = 2*A(x) - 1-x.
(2) A(x) = 2*A(x/A(x)) - 1 - x/A(x).
(3) A(x) = F(x/A(x)) and F(x) = A(x*F(x)) where F(x) = g.f. of A120956.
(4) A(x) = 1+x + Sum{n>=1} x^n * d^n/dx^n (A(x)-1)^(n+1) / (n+1)!. - Paul D. Hanna, Dec 27 2012
a(n) = A120956(n)/2 for n>=2.
a(n) = [x^n] A(x)^n / (2*n) for n>1; i.e., a(n) equals the coefficient of x^n in A(x)^n divided by 2*n.
a(n) ~ c * n^(n + 1/2 + log(2)) / (exp(n) * (log(2))^n), where c = 0.33794865962155... . - Vaclav Kotesovec, Aug 10 2014

A381568 G.f. A(x) satisfies A(x) = (1 + x*A(x*A(x)))^2.

Original entry on oeis.org

1, 2, 5, 22, 126, 884, 7149, 64688, 641836, 6888740, 79203860, 968503090, 12525131474, 170555767116, 2436592516874, 36409825487380, 567612675812796, 9211031425896752, 155283809480528788, 2714788300934206360, 49140787009610861896, 919625415852055598804, 17768937720619971300781
Offset: 0

Views

Author

Seiichi Manyama, Feb 28 2025

Keywords

Crossrefs

Column k=1 of A381567.

Programs

  • PARI
    a(n, k=1) = if(k==0, 0^n, k*sum(j=0, n, binomial(2*n-2*j+2*k, j)/(n-j+k)*a(n-j, j)));

Formula

See A381567.
G.f.: B(x)^2, where B(x) is the g.f. of A143508.

A381602 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of B(x)^k, where B(x) is the g.f. of A120971.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 2, 4, 0, 1, 3, 9, 26, 0, 1, 4, 15, 60, 218, 0, 1, 5, 22, 103, 504, 2151, 0, 1, 6, 30, 156, 870, 4946, 23854, 0, 1, 7, 39, 220, 1329, 8511, 54430, 289555, 0, 1, 8, 49, 296, 1895, 12988, 93070, 655362, 3783568, 0, 1, 9, 60, 385, 2583, 18536, 141316, 1112382, 8496454, 52624689, 0
Offset: 0

Views

Author

Seiichi Manyama, Mar 01 2025

Keywords

Examples

			Square array begins:
  1,     1,     1,     1,      1,      1,      1, ...
  0,     1,     2,     3,      4,      5,      6, ...
  0,     4,     9,    15,     22,     30,     39, ...
  0,    26,    60,   103,    156,    220,    296, ...
  0,   218,   504,   870,   1329,   1895,   2583, ...
  0,  2151,  4946,  8511,  12988,  18536,  25332, ...
  0, 23854, 54430, 93070, 141316, 200930, 273915, ...
		

Crossrefs

Columns k=0..1 give A000007, A120971, A120970(n+1).

Programs

  • PARI
    a(n, k) = if(k==0, 0^n, k*sum(j=0, n, binomial(2*n+k, j)/(2*n+k)*a(n-j, 2*j)));

Formula

See A120971.

A182314 G.f. satisfies: A(x) = 1 + x*A(A(x)^2 - 1).

Original entry on oeis.org

1, 1, 2, 13, 174, 4232, 182382, 14175046, 2045373678, 562261694364, 299983681820740, 314433086095052371, 652379184283729238186, 2691298717301069744228618, 22133007749002207321732828222, 363389633981231330655355989037627, 11920985732676951145747564507103687806
Offset: 0

Views

Author

Paul D. Hanna, Apr 24 2012

Keywords

Examples

			G.f.: A(x) = 1 + x + 2*x^2 + 13*x^3 + 174*x^4 + 4232*x^5 + 182382*x^6 +...
Related expansions:
A(x)^2 = 1 + 2*x + 5*x^2 + 30*x^3 + 378*x^4 + 8864*x^5 + 374093*x^6 +...
A(A(x)^2 - 1) = 1 + 2*x + 13*x^2 + 174*x^3 + 4232*x^4 + 182382*x^5 +...
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+x+x*O(x^n));for(i=1,n,A=1+x*subst(A,x,A^2-1+x*O(x^n)));polcoeff(A,n)}
    for(n=0,25,print1(a(n),", "))

A257813 G.f. satisfies: A(x,y) = 1-x + y*x + Series_Reversion( x/A(x,y)^2 ).

Original entry on oeis.org

1, 0, 1, 0, 2, 0, 0, 4, 5, 0, 0, 8, 38, 14, 0, 0, 16, 184, 262, 42, 0, 0, 32, 720, 2460, 1602, 132, 0, 0, 64, 2480, 16360, 25837, 9260, 429, 0, 0, 128, 7840, 87920, 268134, 237870, 52040, 1430, 0, 0, 256, 23296, 408128, 2109040, 3638386, 2023992, 288494, 4862, 0, 0, 512, 66048, 1701504, 13676128, 40049492, 43815744, 16394336, 1590638, 16796, 0
Offset: 0

Views

Author

Paul D. Hanna, May 10 2015

Keywords

Comments

The rightmost nonzero numbers in this triangle form the Catalan numbers (A000108).

Examples

			This triangle begins:
1;
0, 1;
0, 2, 0;
0, 4, 5, 0;
0, 8, 38, 14, 0;
0, 16, 184, 262, 42, 0;
0, 32, 720, 2460, 1602, 132, 0;
0, 64, 2480, 16360, 25837, 9260, 429, 0;
0, 128, 7840, 87920, 268134, 237870, 52040, 1430, 0;
0, 256, 23296, 408128, 2109040, 3638386, 2023992, 288494, 4862, 0;
0, 512, 66048, 1701504, 13676128, 40049492, 43815744, 16394336, 1590638, 16796, 0;
0, 1024, 180480, 6531840, 76845728, 349863976, 653001202, 487491424, 128720399, 8765044, 58786, 0;
0, 2048, 478720, 23485440, 386423488, 2571281744, 7476451420, 9591548748, 5139351752, 991185638, 48412190, 208012, 0; ...
Row sums (A120970) begin:
[1, 1, 2, 9, 60, 504, 4946, 54430, 655362, 8496454, 117311198, ...],
the g.f. of which satisfies: G(x) = 1 + Series_Reversion(x/G(x)^2).
GENERATING FUNCTION.
G.f.: A(x,y) = 1 + x*y + x^2*(2*y) + x^3*(4*y + 5*y^2) +
x^4*(8*y + 38*y^2 + 14*y^3) +
x^5*(16*y + 184*y^2 + 262*y^3 + 42*y^4) +
x^6*(32*y + 720*y^2 + 2460*y^3 + 1602*y^4 + 132*y^5) +
x^7*(64*y + 2480*y^2 + 16360*y^3 + 25837*y^4 + 9260*y^5 + 429*y^6) +
x^8*(128*y + 7840*y^2 + 87920*y^3 + 268134*y^4 + 237870*y^5 + 52040*y^6 + 1430*y^7) +
x^9*(256*y + 23296*y^2 + 408128*y^3 + 2109040*y^4 + 3638386*y^5 + 2023992*y^6 + 288494*y^7 + 4862*y^8) +...
where
A(x,y) = 1-x + y*x + Series_Reversion( x/A(x,y)^2 ).
RELATED SERIES.
A(x/A(x,y)^2, y) = 1 + y*x + (-2*y^2 + 2*y)*x^2 +
(3*y^3 - 7*y^2 + 4*y)*x^3 +
(-4*y^4 + 6*y^3 - 10*y^2 + 8*y)*x^4 +
(5*y^5 - 27*y^4 - 18*y^3 + 24*y^2 + 16*y)*x^5 +
(-6*y^6 - 14*y^5 - 312*y^4 + 60*y^3 + 240*y^2 + 32*y)*x^6 +
(7*y^7 - 147*y^6 - 1745*y^5 - 1675*y^4 + 2360*y^3 + 1136*y^2 + 64*y)*x^7 +
(-8*y^8 - 348*y^7 - 10744*y^6 - 25146*y^5 + 10246*y^4 + 21616*y^3 + 4256*y^2 + 128*y)*x^8 +
(9*y^9 - 1361*y^8 - 60738*y^7 - 267656*y^6 - 84094*y^5 + 265552*y^4 + 133952*y^3 + 14080*y^2 + 256*y)*x^9 +...
		

Crossrefs

Programs

  • PARI
    {T(n,k) = local(A=[1]);for(i=1,n, A=Vec(1 + (y-1)*x + serreverse(x/Ser(A)^2))); polcoeff(A[n+1],k,y)}
    for(n=0,10,for(k=0,n, print1(T(n,k),", "));print(""))

Formula

G.f. A(x,y) satisfies: A(x/A(x,y)^2, y) = 1+x + (y-1)*x/A(x,y)^2.
Showing 1-9 of 9 results.