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 1-3 of 3 results.

A129289 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+73)^2 = y^2.

Original entry on oeis.org

0, 44, 95, 219, 455, 744, 1460, 2832, 4515, 8687, 16683, 26492, 50808, 97412, 154583, 296307, 567935, 901152, 1727180, 3310344, 5252475, 10066919, 19294275, 30613844, 58674480, 112455452, 178430735, 341980107, 655438583, 1039970712, 1993206308, 3820176192
Offset: 1

Views

Author

Mohamed Bouhamida, May 26 2007

Keywords

Comments

Also values x of Pythagorean triples (x, x+73, y).
Corresponding values y of solutions (x, y) are in A160041.
lim_{n -> infinity} a(n)/a(n-3) = 3+2*sqrt(2).
lim_{n -> infinity} a(n)/a(n-1) = (89+36*sqrt(2))/73 for n mod 3 = {1, 2}.
lim_{n -> infinity} a(n)/a(n-1) = (5907+1802*sqrt(2))/73^2 for n mod 3 = 0.

Crossrefs

Cf. A160041, A129288, A001652, A156035 (decimal expansion of 3+2*sqrt(2)), A160042 (decimal expansion of (89+36*sqrt(2))/73), A160043 (decimal expansion of (5907+1802*sqrt(2))/73^2).

Programs

  • Magma
    m:=25; R:=PowerSeriesRing(Integers(), m); [0] cat Coefficients(R!(x*(44+51*x+124*x^2-28*x^3-17*x^4-28*x^5)/((1-x)*(1-6*x^3+x^6)))); // G. C. Greubel, May 07 2018
  • Mathematica
    Select[Range[0,100000],IntegerQ[Sqrt[#^2+(#+73)^2]]&] (* or *) LinearRecurrence[{1,0,6,-6,0,-1,1},{0,44,95,219,455,744,1460},70] (* Vladimir Joseph Stephan Orlovsky, Feb 02 2012 *)
  • PARI
    {forstep(n=0, 100000000, [3 ,1], if(issquare(2*n^2+146*n+5329), print1(n, ",")))}
    

Formula

a(n) = 6*a(n-3) -a(n-6) +146 for n > 6; a(1)=0, a(2)=44, a(3)=95, a(4)=219, a(5)=455, a(6)=744.
G.f.: x*(44+51*x+124*x^2-28*x^3-17*x^4-28*x^5)/((1-x)*(1-6*x^3+x^6)).
a(3*k+1) = 73*A001652(k) for k >= 0.

Extensions

Edited and two terms added by Klaus Brockhaus, May 04 2009

A160042 Decimal expansion of (89+36*sqrt(2))/73.

Original entry on oeis.org

1, 9, 1, 6, 5, 9, 8, 4, 6, 9, 1, 1, 5, 4, 9, 8, 9, 2, 8, 1, 7, 6, 1, 7, 5, 2, 6, 1, 2, 5, 4, 0, 9, 7, 6, 8, 2, 5, 8, 2, 3, 0, 3, 9, 3, 8, 5, 4, 2, 0, 5, 6, 5, 8, 4, 0, 3, 2, 3, 3, 5, 2, 1, 3, 2, 5, 5, 7, 0, 3, 6, 8, 8, 0, 0, 8, 7, 1, 0, 3, 2, 0, 5, 2, 8, 9, 5, 8, 2, 3, 6, 1, 0, 6, 7, 8, 2, 1, 4, 5, 4, 5, 8, 3, 6
Offset: 1

Views

Author

Klaus Brockhaus, May 04 2009

Keywords

Comments

Equals lim_{n -> infinity} b(n)/b(n-1) for n mod 3 = {1, 2}, b = A129289.
Equals lim_{n -> infinity} b(n)/b(n-1) for n mod 3 = {0, 2}, b = A160041.

Examples

			(89+36*sqrt(2))/73 = 1.91659846911549892817...
		

Crossrefs

Cf. A129289, A160041, A002193 (decimal expansion of sqrt(2)), A160043 (decimal expansion of (5907+1802*sqrt(2))/73^2).

Programs

Formula

Equals (9+2*sqrt(2))/(9-2*sqrt(2)).

A160043 Decimal expansion of (5907+1802*sqrt(2))/73^2.

Original entry on oeis.org

1, 5, 8, 6, 6, 7, 9, 0, 8, 4, 1, 4, 2, 6, 7, 5, 4, 1, 3, 3, 8, 7, 2, 4, 7, 7, 1, 6, 4, 6, 1, 9, 7, 7, 0, 9, 4, 6, 8, 6, 1, 6, 0, 3, 9, 0, 2, 1, 0, 0, 3, 1, 9, 8, 1, 2, 0, 9, 3, 0, 3, 2, 2, 5, 3, 4, 4, 2, 1, 0, 9, 0, 7, 5, 2, 2, 7, 4, 6, 6, 4, 7, 4, 0, 2, 5, 8, 9, 2, 9, 1, 9, 6, 0, 6, 6, 9, 9, 4, 0, 7, 1, 4, 6, 7
Offset: 1

Views

Author

Klaus Brockhaus, May 04 2009

Keywords

Comments

Equals lim_{n -> infinity} b(n)/b(n-1) for n mod 3 = 0, b = A129289.
Equals lim_{n -> infinity} b(n)/b(n-1) for n mod 3 = 1, b = A160041.

Examples

			(5907+1802*sqrt(2))/73^2 = 1.58667908414267541338...
		

Crossrefs

Cf. A129289, A160041, A002193 (decimal expansion of sqrt(2)), A160042 (decimal expansion of (89+36*sqrt(2))/73).

Programs

  • Magma
    (5907+1802*Sqrt(2))/73^2; // G. C. Greubel, Apr 15 2018
  • Mathematica
    RealDigits[(5907 + 1802*Sqrt[2])/73^2, 10, 50][[1]] (* G. C. Greubel, Apr 15 2018 *)
  • PARI
    (5907+1802*sqrt(2))/73^2 \\ G. C. Greubel, Apr 15 2018
    

Formula

Equals (106+17*sqrt(2))/(106-17*sqrt(2)).
Equals (3+2*sqrt(2))*(9-2*sqrt(2))^2/(9+2*sqrt(2))^2.
Showing 1-3 of 3 results.