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.

A122694 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+761)^2 = y^2.

Original entry on oeis.org

0, 583, 820, 2283, 5440, 6783, 15220, 33579, 41400, 90559, 197556, 243139, 529656, 1153279, 1418956, 3088899, 6723640, 8272119, 18005260, 39190083, 48215280, 104944183, 228418380, 281021083, 611661360, 1331321719, 1637912740
Offset: 1

Views

Author

Mohamed Bouhamida, Jun 03 2007

Keywords

Comments

Also values x of Pythagorean triples (x, x+761, y).
Corresponding values y of solutions (x, y) are in A160200.
lim_{n -> infinity} a(n)/a(n-3) = 3+2*sqrt(2) = A156035.
lim_{n -> infinity} a(n)/a(n-1) = (1003+462*sqrt(2))/761 = A160201 for n mod 3 = {1, 2}.
lim_{n -> infinity} a(n)/a(n-1) = (591603+85478*sqrt(2))/761^2 = A160202 for n mod 3 = 0.

Crossrefs

Programs

  • Magma
    I:=[0,583,820,2283,5440,6783,15220]; [n le 7 select I[n] else Self(n-1) +6*Self(n-3) -6*Self(n-4) -Self(n-6) +Self(n-7): n in [1..30]]; // G. C. Greubel, May 04 2018
  • Mathematica
    LinearRecurrence[{1, 0, 6, -6, 0, -1, 1}, {0, 583, 820, 2283, 5440, 6783, 15220}, 27] (* Jean-François Alcover, Nov 13 2017 *)
  • PARI
    {forstep(n=0, 10000000, [3, 1], if(issquare(2*n^2+1522*n+579121), print1(n, ",")))}
    
  • PARI
    x='x+O('x^30); concat([0], Vec(x*(583 +237*x +1463*x^2 -341*x^3 -79*x^4 -341*x^5)/((1-x)*(1 -6*x^3 +x^6)))) \\ G. C. Greubel, May 04 2018
    

Formula

a(n) = 6*a(n-3) -a(n-6) +1522 for n > 6; a(1)=0, a(2)=583, a(3)=820, a(4)=2283, a(5)=5440, a(6)=6783.
G.f.: x*(583 +237*x +1463*x^2 -341*x^3 -79*x^4 -341*x^5)/((1-x)*(1 -6*x^3 +x^6)).
a(3*k+1) = 761*A001652(k) for k >= 0.

Extensions

Edited and one term added by Klaus Brockhaus, May 18 2009

A160201 Decimal expansion of (1003+462*sqrt(2))/761.

Original entry on oeis.org

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

Views

Author

Klaus Brockhaus, May 18 2009

Keywords

Comments

Equals lim_{n -> infinity} b(n)/b(n-1) for n mod 3 = {1, 2}, b = A122694.
Equals lim_{n -> infinity} b(n)/b(n-1) for n mod 3 = {0, 2}, b = A160200.

Examples

			(1003+462*sqrt(2))/761 = 2.17656592091507215840...
		

Crossrefs

Cf. A122694, A160200, A002193 (decimal expansion of sqrt(2)), A160202 (decimal expansion of (591603+85478*sqrt(2))/761^2).

Programs

  • Magma
    (1003+462*Sqrt(2))/761; // G. C. Greubel, Apr 25 2018
  • Mathematica
    RealDigits[(1003+462*Sqrt[2])/761,10,120][[1]] (* Harvey P. Dale, Feb 07 2016 *)
  • PARI
    (1003+462*sqrt(2))/761 \\ G. C. Greubel, Apr 25 2018
    

Formula

Equals (42 +11*sqrt(2))/(42 -11*sqrt(2)).

A160202 Decimal expansion of (591603+85478*sqrt(2))/761^2.

Original entry on oeis.org

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

Views

Author

Klaus Brockhaus, May 18 2009

Keywords

Comments

Equals lim_{n -> infinity} b(n)/b(n-1) for n mod 3 = 0, b = A122694.
Equals lim_{n -> infinity} b(n)/b(n-1) for n mod 3 = 1, b = A160200.

Examples

			(591603+85478*sqrt(2))/761^2 = 1.23029064199800632092...
		

Crossrefs

Cf. A122694, A160200, A002193 (decimal expansion of sqrt(2)), A160201 (decimal expansion of (1003+462*sqrt(2))/761).

Programs

  • Magma
    (591603+85478*Sqrt(2))/761^2; // G. C. Greubel, Apr 25 2018
  • Mathematica
    RealDigits[(591603+85478Sqrt[2])/761^2,10,120][[1]] (* Harvey P. Dale, Oct 25 2011 *)
  • PARI
    (591603+85478*sqrt(2))/761^2 \\ G. C. Greubel, Apr 25 2018
    

Formula

Equals (1082 +79*sqrt(2))/(1082 -79*sqrt(2)).
Eausl (3+2*sqrt(2))*(42-11*sqrt(2))^2/(42+11*sqrt(2))^2.
Showing 1-3 of 3 results.