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.

A130610 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+359)^2 = y^2.

Original entry on oeis.org

0, 40, 901, 1077, 1281, 6160, 7180, 8364, 36777, 42721, 49621, 215220, 249864, 290080, 1255261, 1457181, 1691577, 7317064, 8493940, 9860100, 42647841, 49507177, 57469741, 248570700, 288549840, 334959064, 1448777077, 1681792581
Offset: 1

Views

Author

Mohamed Bouhamida, Jun 17 2007

Keywords

Comments

Also values x of Pythagorean triples (x, x+359, y).
Corresponding values y of solutions (x, y) are in A159844.
For the generic case x^2+(x+p)^2 = y^2 with p = m^2-2 a (prime) number > 7 in A028871, see A118337.
lim_{n -> infinity} a(n)/a(n-3) = 3+2*sqrt(2).
lim_{n -> infinity} a(n)/a(n-1) = (363+38*sqrt(2))/359 for n mod 3 = {1, 2}.
lim_{n -> infinity} a(n)/a(n-1) = (293619+186550*sqrt(2))/359^2 for n mod 3 = 0.

Crossrefs

Cf. A159844, A028871, A118337, A130609, A001652, A156035 (decimal expansion of 3+2*sqrt(2)), A159845 (decimal expansion of (363+38*sqrt(2))/359), A159846 (decimal expansion of (293619+186550*sqrt(2))/359^2).

Programs

  • PARI
    {forstep(n=0, 100000000, [1, 3], if(issquare(2*n^2+718*n+128881), print1(n, ",")))}

Formula

a(n) = 6*a(n-3)-a(n-6)+718 for n > 6; a(1)=0, a(2)=40, a(3)=901, a(4)=1077, a(5)=1281, a(6)=6160.
G.f.: x*(40+861*x+176*x^2-36*x^3-287*x^4-36*x^5) / ((1-x)*(1-6*x^3+x^6)).
a(3*k+1) = 359*A001652(k) for k >= 0.

Extensions

Edited and two terms added by Klaus Brockhaus, Apr 30 2009

A159845 Decimal expansion of (363 + 38*sqrt(2))/359.

Original entry on oeis.org

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

Views

Author

Klaus Brockhaus, Apr 30 2009

Keywords

Comments

Equals lim_{n -> infinity} b(n)/b(n-1) for n mod 3 = {1, 2}, b = A130610.
Equals lim_{n -> infinity} b(n)/b(n-1) for n mod 3 = {0, 2}, b = A159844.

Examples

			(363 + 38*sqrt(2))/359 = 1.16083597596149752605...
		

Crossrefs

Cf. A130610, A159844, A002193 (decimal expansion of sqrt(2)), A159846 (decimal expansion of (293619+186550*sqrt(2))/359^2).

Programs

  • Magma
    (363 +38*Sqrt(2))/359; // G. C. Greubel, May 19 2018
  • Mathematica
    RealDigits[(363 +38*sqrt(2))/359, 10, 100][[1]] (* G. C. Greubel, May 19 2018 *)
  • PARI
    (363 +38*sqrt(2))/359 \\ G. C. Greubel, May 19 2018
    

Formula

Equals (19 + sqrt(2))/(19 - sqrt(2)).

A159846 Decimal expansion of (293619 + 186550*sqrt(2))/359^2.

Original entry on oeis.org

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

Views

Author

Klaus Brockhaus, Apr 30 2009

Keywords

Comments

Equals lim_{n -> infinity} b(n)/b(n-1) for n mod 3 = 0, b = A130610.
Equals lim_{n -> infinity} b(n)/b(n-1) for n mod 3 = 1, b = A159844.

Examples

			(293619 + 186550*sqrt(2))/359^2 = 4.32523444154453240860...
		

Crossrefs

Cf. A130610, A159844, A002193 (decimal expansion of sqrt(2)), A159845 (decimal expansion of (363+38*sqrt(2))/359).

Programs

  • Magma
    (293619 +186550*Sqrt(2))/359^2; // G. C. Greubel, May 19 2018
  • Mathematica
    RealDigits[(293619+186550Sqrt[2])/359^2,10,120][[1]] (* Harvey P. Dale, Jun 14 2011 *)
  • PARI
    (293619 +186550*sqrt(2))/359^2 \\ G. C Greubel, May 19 2018
    

Formula

Equals (650 + 287*sqrt(2))/(650 - 287*sqrt(2)).
Equals (3 + 2*sqrt(2))*(19 - sqrt(2))^2/(19 + sqrt(2))^2.
Showing 1-3 of 3 results.