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 1-5 of 5 results.

A192799 Coefficient of x in the reduction of the n-th Fibonacci polynomial by x^3->x^2+2.

Original entry on oeis.org

0, 1, 0, 2, 2, 5, 12, 22, 54, 109, 242, 520, 1118, 2427, 5218, 11290, 24352, 52579, 113526, 245038, 529068, 1142087, 2465644, 5322896, 11491188, 24807721, 53555508, 115617714, 249599214, 538843277, 1163273304, 2511313222, 5421508714
Offset: 1

Views

Author

Clark Kimberling, Jul 10 2011

Keywords

Comments

For discussions of polynomial reduction, see A192232 and A192744.

Examples

			The first five polynomials p(n,x) and their reductions:
F1(x)=1 -> 1
F2(x)=x -> x
F3(x)=x^2+1 -> x^2+1
F4(x)=x^3+2x -> x^2+2x+2
F5(x)=x^4+3x^2+1 -> 4x^2+2*x+3, so that
A192798=(1,0,1,2,3,...), A192799=(0,1,0,2,2,...), A192800=(0,0,1,1,4,...)
		

Crossrefs

Programs

Formula

a(n) = a(n-1)+3*a(n-2)-3*a(n-4)+a(n-5)+a(n-6).
G.f.: x^2*(x^2+x-1)/(x^6+x^5-3*x^4+3*x^2+x-1). [Colin Barker, Jul 27 2012]

A192800 Coefficient of x^2 in the reduction of the n-th Fibonacci polynomial by x^3->x^2+2.

Original entry on oeis.org

0, 0, 1, 1, 4, 7, 16, 35, 73, 162, 344, 748, 1612, 3478, 7517, 16213, 35020, 75585, 163184, 352295, 760517, 1641880, 3544484, 7652008, 16519388, 35662584, 76989693, 166207785, 358815192, 774622191, 1672280660, 3610176155, 7793770037
Offset: 1

Views

Author

Clark Kimberling, Jul 10 2011

Keywords

Comments

For discussions of polynomial reduction, see A192232 and A192744.

Examples

			The first five polynomials p(n,x) and their reductions:
F1(x)=1 -> 1
F2(x)=x -> x
F3(x)=x^2+1 -> x^2+1
F4(x)=x^3+2x -> x^2+2x+2
F5(x)=x^4+3x^2+1 -> 4x^2+2*x+3, so that
A192798=(1,0,1,2,3,...), A192799=(0,1,0,2,2,...), A192800=(0,0,1,1,4,...)
		

Crossrefs

Programs

Formula

a(n) = a(n-1)+3*a(n-2)-3*a(n-4)+a(n-5)+a(n-6).
G.f.: -x^3/(x^6+x^5-3*x^4+3*x^2+x-1). [Colin Barker, Jul 27 2012]

A192801 Constant term in the reduction of the polynomial (x+2)^n by x^3->x^2+x+1. See Comments.

Original entry on oeis.org

1, 2, 4, 9, 25, 84, 312, 1199, 4637, 17906, 68976, 265249, 1019069, 3913484, 15026092, 57690143, 221487945, 850350482, 3264725772, 12534190569, 48122302705, 184755243892, 709328262928, 2723314511871, 10455585321989, 40141990468066
Offset: 0

Views

Author

Clark Kimberling, Jul 10 2011

Keywords

Comments

For discussions of polynomial reduction, see A192232 and A192744.
If the same reduction is applied to the sequence (x+1)^n instead of (x+2)^n, the resulting three coefficient sequences are essentially as follows:
A078484: constants
A099216: coefficients of x
A115390: coefficients of x^2.

Examples

			The first five polynomials p(n,x) and their reductions:
p(1,x)=1 -> 1
p(2,x)=x+2 -> x+2
p(3,x)=x^2+4x+4 -> x^2+1
p(4,x)=x^3+6x^2+12x+8 -> x^2+4x+4
p(5,x)=x^4+8x^3+24x^2+32x+16 -> 7x^2+13*x+9, so that
A192798=(1,2,4,9,25,...), A192799=(0,1,4,13,42,...), A192800=(0,0,1,7,34,...).
		

Crossrefs

Programs

  • Mathematica
    q = x^3; s = x^2 + x + 1; z = 40;
    p[n_, x_] := (x + 2)^n;
    Table[Expand[p[n, x]], {n, 0, 7}]
    reduce[{p1_, q_, s_, x_}] :=
    FixedPoint[(s PolynomialQuotient @@ #1 +
           PolynomialRemainder @@ #1 &)[{#1, q, x}] &, p1]
    t = Table[reduce[{p[n, x], q, s, x}], {n, 0, z}];
    u1 = Table[Coefficient[Part[t, n], x, 0], {n, 1, z}]  (* A192801 *)
    u2 = Table[Coefficient[Part[t, n], x, 1], {n, 1, z}]
      (* A192802 *)
    u3 = Table[Coefficient[Part[t, n], x, 2], {n, 1, z}]
      (* A192803 *)

Formula

a(n) = 7*a(n-1)-15*a(n-2)+11*a(n-3).
G.f.: -(5*x^2-5*x+1)/(11*x^3-15*x^2+7*x-1). [Colin Barker, Jul 27 2012]

Extensions

Recurrence corrected by Colin Barker, Jul 27 2012

A192802 Coefficient of x in the reduction of the polynomial (x+2)^n by x^3->x^2+x+1.

Original entry on oeis.org

0, 1, 4, 13, 42, 143, 514, 1915, 7268, 27805, 106680, 409633, 1573086, 6040587, 23193782, 89051615, 341901032, 1312664601, 5039704492, 19348873781, 74285859698, 285204660583, 1094982340202, 4203950929347, 16140172668812
Offset: 0

Views

Author

Clark Kimberling, Jul 10 2011

Keywords

Comments

For discussions of polynomial reduction, see A192232 and A192744.

Examples

			The first five polynomials p(n,x) and their reductions:
p(1,x)=1 -> 1
p(2,x)=x+2 -> x+2
p(3,x)=x^2+4x+4 -> x^2+1
p(4,x)=x^3+6x^2+12x+8 -> x^2+4x+4
p(5,x)=x^4+8x^3+24x^2+32x+16 -> 7x^2+13*x+9, so that
A192798=(1,2,4,9,25,...), A192799=(0,1,4,13,42,...), A192800=(0,0,1,7,34,...).
		

Crossrefs

Programs

Formula

a(n) = 7*a(n-1)-15*a(n-2)+11*a(n-3).
G.f.: x*(3*x-1)/(11*x^3-15*x^2+7*x-1). - Colin Barker, Jul 27 2012

Extensions

Recurrence corrected by Colin Barker, Jul 27 2012

A192803 Coefficient of x^2 in the reduction of the polynomial (x+2)^n by x^3->x^2+x+1.

Original entry on oeis.org

0, 0, 1, 7, 34, 144, 575, 2239, 8632, 33164, 127297, 488571, 1875346, 7199124, 27637959, 106107659, 407374592, 1564024808, 6004739025, 23053921567, 88510638482, 339817775144, 1304657986015, 5008956298247, 19230819824088, 73832632141076
Offset: 0

Views

Author

Clark Kimberling, Jul 10 2011

Keywords

Comments

For discussions of polynomial reduction, see A192232 and A192744.

Examples

			The first five polynomials p(n,x) and their reductions:
p(1,x)=1 -> 1
p(2,x)=x+2 -> x+2
p(3,x)=x^2+4x+4 -> x^2+1
p(4,x)=x^3+6x^2+12x+8 -> x^2+4x+4
p(5,x)=x^4+8x^3+24x^2+32x+16 -> 7x^2+13*x+9, so that
A192798=(1,2,4,9,25,...), A192799=(0,1,4,13,42,...), A192800=(0,0,1,7,34,...).
		

Crossrefs

Programs

Formula

a(n) = 7*a(n-1)-15*a(n-2)+11*a(n-3).
G.f.: -x^2/(11*x^3-15*x^2+7*x-1). [Colin Barker, Jul 27 2012]

Extensions

Recurrence corrected by Colin Barker, Jul 27 2012
Showing 1-5 of 5 results.