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.

A129626 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+281)^2 = y^2.

Original entry on oeis.org

0, 76, 559, 843, 1239, 3976, 5620, 7920, 23859, 33439, 46843, 139740, 195576, 273700, 815143, 1140579, 1595919, 4751680, 6648460, 9302376, 27695499, 38750743, 54218899, 161421876, 225856560, 316011580, 940836319, 1316389179, 1841851143, 5483596600
Offset: 1

Views

Author

Mohamed Bouhamida, May 30 2007

Keywords

Comments

Also values x of Pythagorean triples (x, x+281, y).
Corresponding values y of solutions (x, y) are in A157348.
lim_{n -> infinity} a(n)/a(n-3) = 3+2*sqrt(2).
lim_{n -> infinity} a(n)/a(n-1) = (297+68*sqrt(2))/281 for n mod 3 = {1, 2}.
lim_{n -> infinity} a(n)/a(n-1) = (130803+73738*sqrt(2))/281^2 for n mod 3 = 0.

Crossrefs

Cf. A157348, A001652, A129288, A129289, A129298, A156035 (decimal expansion of 3+2*sqrt(2)), A157349 (decimal expansion of (297+68*sqrt(2))/281), A157350 (decimal expansion of (130803+73738*sqrt(2))/281^2).

Programs

  • Mathematica
    LinearRecurrence[{1, 0, 6, -6, 0, -1, 1}, {0, 76, 559, 843, 1239, 3976, 5620}, 40] (* Vladimir Joseph Stephan Orlovsky, Feb 13 2012 *)
  • PARI
    {forstep(n=0, 1000000000, [3, 1], if(issquare(2*n^2+562*n+78961), print1(n, ",")))}

Formula

a(n) = 6*a(n-3)-a(n-6)+562 for n > 6; a(1)=0, a(2)=76, a(3)=559, a(4)=843, a(5)=1239, a(6)=3976.
G.f.: x*(76+483*x+284*x^2-60*x^3-161*x^4-60*x^5)/((1-x)*(1-6*x^3+x^6)).
a(3*k+1) = 281*A001652(k) for k >= 0.

Extensions

Edited by Klaus Brockhaus, Apr 12 2009

A157349 Decimal expansion of (297 + 68*sqrt(2))/281.

Original entry on oeis.org

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

Views

Author

Klaus Brockhaus, Apr 12 2009

Keywords

Comments

lim_{n -> infinity} b(n)/b(n-1) = (297+68*sqrt(2))/281 for n mod 3 = {1, 2}, b = A129626.
lim_{n -> infinity} b(n)/b(n-1) = (297+68*sqrt(2))/281 for n mod 3 = {0, 2}, b = A157348.

Examples

			(297 + 68*sqrt(2))/281 = 1.39916911829669204027...
		

Crossrefs

Cf. A129626, A157348, A002193 (decimal expansion of sqrt(2)), A157350 (decimal expansion of (130803+73738*sqrt(2))/281^2).

Programs

  • Magma
    (297+68*Sqrt(2))/281; // G. C. Greubel, Feb 01 2018
  • Mathematica
    RealDigits[(297 + 68*Sqrt[2])/281, 10, 100][[1]] (* G. C. Greubel, Feb 01 2018 *)
  • PARI
    (297+68*sqrt(2))/281 \\ G. C. Greubel, Feb 01 2018
    

Formula

(297 + 68*sqrt(2))/281 = (17 + 2*sqrt(2))/(17 - 2*sqrt(2)).

A157350 Decimal expansion of (130803 + 73738*sqrt(2))/281^2.

Original entry on oeis.org

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

Views

Author

Klaus Brockhaus, Apr 12 2009

Keywords

Comments

lim_{n -> infinity} b(n)/b(n-1) = (130803+73738*sqrt(2))/281^2 for n mod 3 = 0, b = A129626.
lim_{n -> infinity} b(n)/b(n-1) = (130803+73738*sqrt(2))/281^2 for n mod 3 = 1, b = A157348.

Examples

			(130803 + 73738*sqrt(2))/281^2 = 2.97722014237746840476...
		

Crossrefs

Cf. A129626, A157348, A002193 (decimal expansion of sqrt(2)), A156035 (decimal expansion of 3+2*sqrt(2)), A157349 (decimal expansion of (297+68*sqrt(2))/281).

Programs

  • Magma
    (130803+73738*Sqrt(2))/281^2 // G. C. Greubel, Feb 01 2018
  • Mathematica
    RealDigits[(130803 + 73738*Sqrt[2])/281^2, 10, 100][[1]] (* G. C. Greubel, Feb 01 2018 *)
  • PARI
    (130803+73738*sqrt(2))/281^2 \\ G. C. Greubel, Feb 01 2018
    

Formula

(130803 + 73738*sqrt(2))/281^2 = (458 + 161*sqrt(2))/(458 - 161*sqrt(2)) = (3 + 2*sqrt(2))*(17 - 2*sqrt(2))^2/(17 + 2*sqrt(2))^2.
Showing 1-3 of 3 results.