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 1-8 of 8 results.

A179407 Values x for records of minima of positive distance d between a fifth power of positive integer x and a square of integer y such d = x^5 - y^2 (x != k^2 and y != k^5).

Original entry on oeis.org

8, 55, 76, 377, 430, 499, 655, 804, 1827, 5350, 10805, 15433, 22108, 44729, 44817, 96001, 747343, 748635, 952463, 7626590, 10741787, 12798893, 14957531, 15873532
Offset: 1

Views

Author

Artur Jasinski, Jul 13 2010

Keywords

Comments

Distance d is equal to 0 when x = k^2 and y = k^5.
For d values, see A179406.
For y values, see A179408.
Conjecture (from Artur Jasinski):
For any positive number x >= A179407(n), the distance d between the fifth power of x and the square of any y (such that x != k^2 and y != k^5) can't be less than A179406(n).

Crossrefs

Programs

  • Mathematica
    max = 1000; vecd = Table[10^100, {n, 1, max}]; vecx = Table[10^100, {n, 1, max}]; vecy = Table[10^100, {n, 1, max}]; len = 1; Do[m = Floor[(n^5)^(1/2)]; k = n^5 - m^2; If[k != 0, ile = 0; Do[If[vecd[[z]] < k, ile = ile + 1], {z, 1, len}]; len = ile + 1; vecd[[len]] = k; vecx[[len]] = n; vecy[[len]] = m], {n, 1, 96001}]; dd = {}; xx = {}; yy = {}; Do[AppendTo[dd, vecd[[n]]]; AppendTo[xx, vecx[[n]]]; AppendTo[yy, vecy[[n]]], {n, 1, len}]; xx (* Artur Jasinski, Jul 13 2010 *)

Formula

a(n)^5-A179408(n)^2 = A179406(n).

A179408 Values y for records of minima of positive distance d between a fifth power of a positive integer x and a square of an integer y such d = x^5 - y^2 (x != k^2 and y != k^5).

Original entry on oeis.org

181, 22434, 50354, 2759646, 3834168, 5562261, 10980023, 18329057, 142674503, 2093555387, 12135618855, 29588700403, 72673092233, 423129175811, 425213412449, 2855547523353, 482836315990072, 484925830443335
Offset: 1

Views

Author

Artur Jasinski, Jul 13 2010

Keywords

Comments

Distance d is equal to 0 when x = k^2 and y = k^5.
For d values, see A179406.
For x values, see A179407.
Conjecture (from Artur Jasinski):
For any positive number x >= A179407(n), the distance d between fifth power of x and the square of any y (such that x != k^2 and y != k^5) can't be less than A179406(n).

Crossrefs

Programs

  • Mathematica
    max = 1000; vecd = Table[10^100, {n, 1, max}]; vecx = Table[10^100, {n, 1, max}]; vecy = Table[10^100, {n, 1, max}]; len = 1; Do[m = Floor[(n^5)^(1/2)]; k = n^5 - m^2; If[k != 0, ile = 0; Do[If[vecd[[z]] < k, ile = ile + 1], {z, 1, len}]; len = ile + 1; vecd[[len]] = k; vecx[[len]] = n; vecy[[len]] = m], {n, 1, 96001}]; dd = {}; xx = {}; yy = {}; Do[AppendTo[dd, vecd[[n]]]; AppendTo[xx, vecx[[n]]]; AppendTo[yy, vecy[[n]]], {n, 1, len}]; yy (* Artur Jasinski, Jul 13 2010 *)

Formula

A179407(n)^5-a(n)^2 = A179406(n).

A198443 Conjectured record minima of the positive distance d between the square of an integer y and the fifth power of a positive integer x such that d = y^2 - x^5 (x <> k^2 and y <> k^5).

Original entry on oeis.org

3, 4, 11, 26, 37, 368, 1828, 2180, 7825, 8177, 8217, 71393, 72481, 75154, 118409, 175485, 203697, 206370, 1049148, 1058224, 1843945, 1846618, 8186369, 8197633, 9600802, 96020524, 169503449, 294638801, 305158594, 305192969, 657099024
Offset: 1

Views

Author

Artur Jasinski, Oct 25 2011

Keywords

Comments

Distance d is equal to 0 when x = k^2 and y = k^5.
Only the values of x < 10^8 have been searched/
For x values see A198444.
For y values see A198445.
Conjecture: For any positive number x >= A198444(n), the distance d between the square of an integer y and the fifth power of a positive integer x (such that x <> k^2 and y <> k^5) can't be less than A198443(n).

Crossrefs

Programs

  • Mathematica
    max = 1000; vecd = Table[10^100, {n, 1, max}]; vecx = Table[10^100, {n, 1, max}]; vecy = Table[10^100, {n, 1, max}]; len = 1; Do[m = Floor[(n^5)^(1/2)] + 1; k = m^2 - n^5; If[k != 0, ile = 0; Do[If[vecd[[z]] < k, ile = ile + 1], {z, 1, len}]; len = ile + 1; vecd[[len]] = k; vecx[[len]] = n; vecy[[len]] = m], {n, 1, 100000000}]; dd = {}; xx = {}; yy = {}; Do[AppendTo[dd, vecd[[n]]];  AppendTo[xx, vecx[[n]]]; AppendTo[yy, vecy[[n]]], {n, 1, len}]; dd

Formula

a(n) = (A198445(n))^2 - (A198444(n))^5.

A198444 Values x for record minima of the positive distance d between the square of an integer y and the fifth power of a positive integer x such that d = y^2 - x^5 (x <> k^2 and y <> k^5).

Original entry on oeis.org

1, 2, 5, 23, 27, 73, 96, 104, 396, 404, 432, 686, 723, 735, 1130, 1159, 2019, 2031, 3861, 5310, 18219, 18231, 25592, 25608, 44367, 200141, 213842, 308228, 390615, 390635, 549976, 631544, 1579129, 1657086, 2941211, 2941239, 5523608
Offset: 1

Views

Author

Artur Jasinski, Oct 25 2011

Keywords

Comments

Distance d is equal to 0 when x = k^2 and y = k^5.
For d values see A198443.
For y values see A198445.
Conjecture: For any positive number x >= A198444(n), the distance d between the square of an integer y and the fifth power of x (such that x <> k^2 and y <> k^5) can't be less than A198443(n).

Crossrefs

Programs

  • Mathematica
    max = 1000; vecd = Table[10^100, {n, 1, max}]; vecx = Table[10^100, {n, 1, max}]; vecy = Table[10^100, {n, 1, max}]; len = 1; Do[m = Floor[(n^5)^(1/2)] + 1; k = m^2 - n^5; If[k != 0, ile = 0; Do[If[vecd[[z]] < k, ile = ile + 1], {z, 1, len}]; len = ile + 1; vecd[[len]] = k; vecx[[len]] = n; vecy[[len]] = m], {n, 1, 100000000}]; dd = {}; xx = {}; yy = {}; Do[AppendTo[dd, vecd[[n]]]; AppendTo[xx, vecx[[n]]]; AppendTo[yy, vecy[[n]]], {n, 1, len}]; vecx

A198445 Values y of record minima of the positive distance d between the square of an integer y and the fifth power of a positive integer x such that d = y^2 - x^5 (x <> k^2 and y <> k^5).

Original entry on oeis.org

2, 6, 56, 2537, 3788, 45531, 90298, 110302, 3120599, 3280601, 3878907, 12325663, 14055482, 14645977, 42923597, 45730778, 183164286, 185898039, 926295393, 2054642668, 44803437862, 44877249113, 104775699199, 104939539201, 414619915847, 17920089051165, 21146208937291, 52744869326263, 95361328242187, 9537353527343
Offset: 1

Views

Author

Artur Jasinski, Oct 25 2011

Keywords

Comments

Distance d is equal to 0 when x = k^2 and y = k^5.
For d values see A198443.
For x values see A198444.
Conjecture: For any positive number x >= A198444(n), the distance d between the square of an integer y and the fifth power of x (such that x <> k^2 and y <> k^5) can't be less than A198443(n).

Crossrefs

Programs

  • Mathematica
    max = 1000; vecd = Table[10^100, {n, 1, max}]; vecx = Table[10^100, {n, 1, max}]; vecy = Table[10^100, {n, 1, max}]; len = 1; Do[m = Floor[(n^5)^(1/2)] + 1; k = m^2 - n^5; If[k != 0, ile = 0; Do[If[vecd[[z]] < k, ile = ile + 1], {z, 1, len}]; len = ile + 1; vecd[[len]] = k; vecx[[len]] = n; vecy[[len]] = m], {n, 1, 100000000}]; dd = {}; xx = {}; yy = {}; Do[AppendTo[dd, vecd[[n]]]; AppendTo[xx, vecx[[n]]]; AppendTo[yy, vecy[[n]]], {n, 1, len}]; vecy

A179447 Smallest values d such that the equation d =x^5-y^2 has exactly n distinct nonnegative integer solutions.

Original entry on oeis.org

2, 1, 7, 1044976, 11331151
Offset: 0

Views

Author

Artur Jasinski, Jul 14 2010

Keywords

Comments

a(0)=2 because no integer solutions x^5-y^2 = 2;
a(1)=1 because 1=1^5-0^2;
a(2)=7 because 7=2^5-5^2 and 7=8^5-181^2;
a(3)=1044976 because 1044976=16^5-60^2 and 1044976=20^5-1468^2 and 1044976=41^5-10715^2;
a(4)=11331151 because 11331151=35^5-6418^2 and 11331151=40^5-9543^2 and 11331151=56^5-23225^2 and 11331151=386^5-2927305^2.

Crossrefs

A198393 Rank of hyperelliptic curve y^2 = x^5 - n.

Original entry on oeis.org

1, 0, 0, 0, 2, 0, 2, 1, 0, 1, 0, 1, 2, 1, 0, 1, 1, 2, 1, 0, 2, 1, 1, 1, 1, 1, 1, 2, 0, 0, 1, 1, 1, 1, 0, 0, 2, 2, 0, 1, 1, 1, 2, 1, 1, 2, 2, 1, 0, 2, 0, 0, 1, 2, 1, 0, 1, 1, 2, 2, 1, 0, 2, 1, 3, 1, 2, 1, 0, 0, 1, 0, 2, 3, 1, 0, 2, 1, 1, 0, 1, 1, 2, 1, 1, 3, 1, 0, 1, 2, 0, 0, 1, 2, 1, 0, 1, 1, 1, 1
Offset: 1

Views

Author

Artur Jasinski, Oct 24 2011

Keywords

Comments

If a(n)=0 number of rational points of hyperelliptic curve is finite and if a(n)<>0 then is infinite. For n when a(n)=0 see A198394.

Crossrefs

Programs

  • Magma
    _ := PolynomialRing(Rationals());
    for n := 1 to 100 do
    C := HyperellipticCurve(x^5-n);
    J := Jacobian(C);
    RankBound(J)

A179448 Numbers d such that the equation d =x^5-y^2 has more than 2 distinct nonnegative integer solutions.

Original entry on oeis.org

1044976, 1541468, 11331151, 15579791, 16410368, 33543196, 46539324, 72697500, 302272796, 528292607
Offset: 1

Views

Author

Artur Jasinski, Jul 14 2010

Keywords

Examples

			a(1)=1044976 because 1044976=16^5-60^2 and 1044976=20^5-1468^2 and 1044976=41^5-10715^2;
a(3)=11331151 because 11331151=35^5-6418^2 and 11331151=40^5-9543^2 and 11331151=56^5-23225^2 and 11331151=386^5-2927305^2.
		

Crossrefs

Showing 1-8 of 8 results.