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 1-9 of 9 results.

A207060 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x+401)^2 = y^2.

Original entry on oeis.org

0, 259, 496, 1203, 2596, 3939, 8020, 16119, 23940, 47719, 94920, 140503, 279096, 554203, 819880, 1627659, 3231100, 4779579, 9487660, 18833199, 27858396, 55299103, 109768896, 162371599, 322307760, 639780979, 946372000, 1878548259, 3728917780, 5515861203
Offset: 1

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[ {1, 0, 6, -6, 0, -1, 1}, {0, 259, 496, 1203, 2596, 3939, 8020}, 50]

Formula

G.f.: x^2*(161*x^5+79*x^4+161*x^3-707*x^2-237*x-259)/((x-1)*(x^6-6*x^3+1)). - Colin Barker, Aug 05 2012

A207061 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x+433)^2 = y^2.

Original entry on oeis.org

0, 92, 935, 1299, 1775, 6552, 8660, 11424, 39243, 51527, 67635, 229772, 301368, 395252, 1340255, 1757547, 2304743, 7812624, 10244780, 13434072, 45536355, 59711999, 78300555, 265406372, 348028080, 456370124, 1546902743, 2028457347, 2659921055, 9016010952
Offset: 1

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[ {1, 0, 6, -6, 0, -1, 1}, {0, 92, 935, 1299, 1775, 6552, 8660}, 50]

Formula

G.f.: x^2*(76*x^5+281*x^4+76*x^3-364*x^2-843*x-92)/((x-1)*(x^6-6*x^3+1)). - Colin Barker, Aug 05 2012

A207075 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x+479)^2 = y^2.

Original entry on oeis.org

0, 280, 637, 1437, 2937, 4960, 9580, 18300, 30081, 57001, 107821, 176484, 333384, 629584, 1029781, 1944261, 3670641, 6003160, 11333140, 21395220, 34990137, 66055537, 124701637, 203938620, 385001040, 726815560, 1188642541, 2243951661, 4236192681, 6927917584
Offset: 1

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[ {1, 0, 6, -6, 0, -1, 1}, {0, 280, 637, 1437, 2937, 4960, 9580}, 50]

Formula

G.f.: x^2*(180*x^5 + 119*x^4 + 180*x^3 - 800*x^2 - 357*x - 280)/((x-1)*(x^6-6*x^3+1)). [Colin Barker, Aug 05 2012]

A207076 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x+487)^2 = y^2.

Original entry on oeis.org

0, 185, 836, 1461, 2436, 6125, 9740, 15405, 36888, 57953, 90968, 216177, 338952, 531377, 1261148, 1976733, 3098268, 7351685, 11522420, 18059205, 42849936, 67158761, 105257936, 249748905, 391431120, 613489385, 1455644468, 2281428933, 3575679348, 8484118877
Offset: 1

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[ {1, 0, 6, -6, 0, -1, 1}, {0, 185, 836, 1461, 2436, 6125, 9740}, 50]

Formula

G.f.: x^2*(135*x^5+217*x^4+135*x^3-625*x^2-651*x-185)/((x-1)*(x^6-6*x^3+1)). [Colin Barker, Aug 05 2012]

A207077 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x+497)^2 = y^2.

Original entry on oeis.org

0, 91, 216, 355, 387, 528, 568, 795, 1120, 1491, 1960, 2635, 3408, 3588, 4387, 4615, 5916, 7791, 9940, 12663, 16588, 21087, 22135, 26788, 28116, 35695, 46620, 59143, 75012, 97887, 124108, 130216, 157335, 165075, 209248, 272923, 345912, 438403, 571728, 724555
Offset: 1

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[ {1, 0, 0, 0, 0, 0, 0, 0, 6, -6, 0, 0, 0, 0, 0, 0, 0, -1, 1}, {0, 91, 216, 355, 387, 528, 568, 795, 1120, 1491, 1960, 2635, 3408, 3588, 4387, 4615, 5916, 7791, 9940}, 50]

Formula

G.f.: x^2*(77*x^17 +75*x^16 +61*x^15 +12*x^14 +47*x^13 +12*x^12 +61*x^11 +75*x^10 +77*x^9 -371*x^8 -325*x^7 -227*x^6 -40*x^5 -141*x^4 -32*x^3 -139*x^2 -125*x -91)/((x -1)*(x^18 -6*x^9 +1)). - Colin Barker, Aug 05 2012

A309998 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x + 529)^2 = y^2.

Original entry on oeis.org

0, 276, 287, 740, 759, 1587, 3059, 3120, 5687, 5796, 10580, 19136, 19491, 34440, 35075, 62951, 112815, 114884, 202011, 205712, 368184, 658812, 670871, 1178684, 1200255, 2147211, 3841115, 3911400, 6871151, 6996876, 12516140, 22388936, 22798587, 40049280, 40782059, 72950687
Offset: 1

Views

Author

Mohamed Bouhamida, Aug 26 2019

Keywords

Comments

For the generic case x^2 + (x + p^2)^2 = y^2 with p = m^2 - 2 a prime number in A028871, m>=5, (0; p^2) and (2*m^3 + 2*m^2 - 4*m - 4; m^4 + 2*m^3 - 4*m - 4) are solutions.

Crossrefs

Cf. A207059.

Programs

  • Mathematica
    Rest@ CoefficientList[Series[x^2*(276 + 11 x + 453 x^2 + 19 x^3 + 828 x^4 - 184 x^5 - 5 x^6 - 151 x^7 - 5 x^8 - 184 x^9)/((1 - x) (1 - 6 x^5 + x^10)), {x, 0, 36}], x] (* Michael De Vlieger, Sep 29 2019 *)
  • PARI
    concat(0, Vec(x^2*(276 + 11*x + 453*x^2 + 19*x^3 + 828*x^4 - 184*x^5 - 5*x^6 - 151*x^7 - 5*x^8 - 184*x^9) / ((1 - x)*(1 - 6*x^5 + x^10)) + O(x^40))) \\ Colin Barker, Aug 27 2019

Formula

a(n) = 6*a(n-5) - a(n-10) + 1058 with a(0) = 0, a(1) = 276, a(2) = 287, a(3) = 740, a(4) = 759, a(5) = 1587, a(6) = 3059, a(7) = 3120, a(8) = 5687, a(9) = 5796.
From Colin Barker, Aug 27 2019: (Start)
G.f.: x^2*(276 + 11*x + 453*x^2 + 19*x^3 + 828*x^4 - 184*x^5 - 5*x^6 - 151*x^7 - 5*x^8 - 184*x^9) / ((1 - x)*(1 - 6*x^5 + x^10)).
a(n) = a(n-1) + 6*a(n-5) - 6*a(n-6) - a(n-10) + a(n-11) for n>11.
(End)

A201916 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+2737)^2 = y^2.

Original entry on oeis.org

0, 75, 203, 323, 552, 708, 1020, 1127, 1311, 1428, 1608, 1820, 1955, 2336, 2675, 3128, 3311, 3627, 3927, 4140, 4508, 4743, 5535, 6003, 6800, 7280, 7848, 8211, 8588, 9240, 9860, 11063, 11895, 13583, 14168, 15180, 15827, 16827, 18011, 18768, 20915, 22836
Offset: 1

Views

Author

T. D. Noe, Feb 09 2012

Keywords

Comments

Note that 2737 = 7 * 17 * 23, the product of the first three distinct primes in A058529 (and A001132) and hence the smallest such number. This sequence satisfies a linear difference equation of order 55 whose 55 initial terms can be found by running the Mathematica program.
There are many sequences like this one. What determines the order of the linear difference equation? All primes p have order 7. For those p, it appears that p^2 has order 11, p^3 order 15, and p^i order 3+4*i. It appears that for semiprimes p*q (with p > q), the order is 19. What is the next term of the sequence beginning 3, 7, 19, 55, 163? This could be sequence A052919, which is 1 + 2*3^f, where f is the number of primes.
The crossref list is thought to be complete up to Feb 14 2012.

Crossrefs

Cf. A001652 (1), A076296 (7), A118120 (17), A118337 (23), A118674 (31).
Cf. A129288 (41), A118675 (47), A118554 (49), A118673 (71), A129289 (73).
Cf. A118676 (79), A129298 (89), A129836 (97), A157119 (103), A161478 (113).
Cf. A129837 (119), A129992 (127), A129544 (137), A161482 (151).
Cf. A206426 (161), A130608 (167), A161486 (191), A185394 (193).
Cf. A129993 (199), A198294 (217), A130609 (223), A129625 (233).
Cf. A204765 (239), A129991 (241), A207058 (263), A129626 (281).
Cf. A205644 (287), A207059 (289), A129640 (313), A205672 (329).
Cf. A129999 (337), A118611 (343), A130610 (359), A207060 (401).
Cf. A129641 (409), A207061 (433), A130645 (439), A130004 (449).
Cf. A129642 (457), A129725 (521), A101152 (569), A130005 (577).
Cf. A207075 (479), A207076 (487), A207077 (497), A207078 (511).
Cf. A111258 (601), A115135 (617), A130013 (647), A130646 (727).
Cf. A122694 (761), A123654 (809), A129010 (833), A130647 (839).
Cf. A129857 (857), A130014 (881), A129974 (937), A129975 (953).
Cf. A130017 (967), A118630 (2401), A118576 (16807).

Programs

  • Mathematica
    d = 2737; terms = 100; t = Select[Range[0, 55000], IntegerQ[Sqrt[#^2 + (#+d)^2]] &]; Do[AppendTo[t, t[[-1]] + 6*t[[-27]] - 6*t[[-28]] - t[[-54]] + t[[-55]]], {terms-55}]; t

Formula

a(n) = a(n-1) + 6*a(n-27) - 6*a(n-28) - a(n-54) + a(n-55), where the 55 initial terms can be computed using the Mathematica program.
G.f.: x^2*(73*x^53 +116*x^52 +100*x^51 +171*x^50 +104*x^49 +184*x^48 +57*x^47 +92*x^46 +55*x^45 +80*x^44 +88*x^43 +53*x^42 +139*x^41 +113*x^40 +139*x^39 +53*x^38 +88*x^37 +80*x^36 +55*x^35 +92*x^34 +57*x^33 +184*x^32 +104*x^31 +171*x^30 +100*x^29 +116*x^28 +73*x^27 -363*x^26 -568*x^25 -480*x^24 -797*x^23 -468*x^22 -792*x^21 -235*x^20 -368*x^19 -213*x^18 -300*x^17 -316*x^16 -183*x^15 -453*x^14 -339*x^13 -381*x^12 -135*x^11 -212*x^10 -180*x^9 -117*x^8 -184*x^7 -107*x^6 -312*x^5 -156*x^4 -229*x^3 -120*x^2 -128*x -75) / ((x -1)*(x^54 -6*x^27 +1)). - Colin Barker, May 18 2015

A331265 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x + 31^2)^2 = y^2.

Original entry on oeis.org

0, 279, 656, 1139, 1860, 2883, 4340, 6419, 9156, 13299, 19220, 27683, 39780, 55719, 79856, 114359, 163680, 234183, 327080, 467759, 668856, 956319, 1367240, 1908683, 2728620, 3900699, 5576156, 7971179, 11126940, 15905883, 22737260, 32502539, 46461756, 64854879, 92708600, 132524783
Offset: 1

Views

Author

Mohamed Bouhamida, Feb 12 2020

Keywords

Comments

For the generic case x^2 + (x + p^2)^2 = y^2 with p = 2*m^2 - 1 a (prime) number in A066436, m >= 4 (means p >= 31), the first five consecutive solutions are (0, p^2), (4*m^3+2*m^2-2*m-1, 4*m^4+4*m^3-2*m-1), (8*m^3+8*m^2+4*m, 4*m^4+8*m^3+12*m^2+4*m+1), (12*m^4-40*m^3+44*m^2-20*m+3, 20*m^4-56*m^3+60*m^2-28*m+5), (12*m^4-20*m^3+2*m^2+10*m-4, 20*m^4-28*m^3+14*m-5) and the other solutions are defined by (X(n), Y(n)) = (3*X(n-5) + 2*Y(n-5) + p^2, 4*X(n-5) + 3*Y(n-5) + 2*p^2).
X(n) = 6*X(n-5) - X(n-10) + 2*p^2, and Y(n) = 6*Y(n-5) - Y(n-10) (can be easily proved using X(n) = 3*X(n-5) + 2*Y(n-5) + p^2, and Y(n) = 4*X(n-5) + 3*Y(n-5) + 2*p^2).

Examples

			For p=31 (m=4) the first five (5) consecutive solutions are (0, 961), (279, 1271), (656, 1745), (1139, 2389), (1860, 3379).
		

Crossrefs

Cf. A066436 (Primes of the form 2*m^2 - 1).
Solutions x to x^2+(x+p^2)^2=y^2: A118554 (p=7), A207059 (p=17), A309998 (p=23), this sequence (p=31), A332000 (p=47).

Programs

  • Magma
    I:=[0, 279, 656, 1139, 1860, 2883, 4340, 6419, 9156, 13299]; [n le 10 select I[n] else 6*Self(n-5) - Self(n-10)+1922: n in [1..100]];
    
  • Mathematica
    LinearRecurrence[{1, 0, 0, 0, 6, -6, 0, 0, 0, -1, 1}, {0, 279, 656, 1139, 1860, 2883, 4340, 6419, 9156, 13299, 19220}, 36] (* Jean-François Alcover, Feb 12 2020 *)
  • PARI
    concat(0, Vec(x^2*(279 + 377*x + 483*x^2 + 721*x^3 + 1023*x^4 - 217*x^5 - 183*x^6 - 161*x^7 - 183*x^8 - 217*x^9) / ((1 - x)*(1 - 6*x^5 + x^10)) + O(x^30))) \\ Colin Barker, Feb 12 2020

Formula

a(n) = 6*a(n-5) - a(n-10) + 1922 for n >= 11; a(1)=0, a(2)=279, a(3)=656, a(4)=1139, a(5)=1860, a(6)=2883, a(7)=4340, a(8)=6419, a(9)=9156, a(10)=13299.
From Colin Barker, Feb 12 2020: (Start)
G.f.: x^2*(279 + 377*x + 483*x^2 + 721*x^3 + 1023*x^4 - 217*x^5 - 183*x^6 - 161*x^7 - 183*x^8 - 217*x^9) / ((1 - x)*(1 - 6*x^5 + x^10)).
a(n) = a(n-1) + 6*a(n-5) - 6*a(n-6) - a(n-10) + a(n-11) for n>11.
(End)

A332000 Nonnegative values x of solutions (x, y) to the Diophantine equation x^2 + (x + 47^2)^2 = y^2.

Original entry on oeis.org

0, 752, 1820, 2231, 3995, 6627, 10575, 16511, 18840, 28952, 44180, 67116, 101664, 115227, 174135, 262871, 396539, 597891, 676940, 1020276, 1537464, 2316536, 3490100, 3950831, 5951939, 8966331, 13507095, 20347127, 23032464, 34695776, 52264940, 78730452, 118597080, 134248371
Offset: 1

Views

Author

Mohamed Bouhamida, Feb 04 2020

Keywords

Comments

For the generic case x^2 + (x + p^2)^2 = y^2 with p = m^2 - 2 a (prime) number in A028871, m>=7 (means p>=47), the first five consecutive solutions are: (0; p^2), (2*m^3+2*m^2-4*m-4; m^4+2*m^3-4*m-4), (4*m^3+8*m^2+8*m; m^4+4*m^3+12*m^2+8*m+4), (3*m^4-20*m^3+44*m^2-40*m+12; 5*m^4-28*m^3+60*m^2-56*m+20), (3*m^4-10*m^3+2*m^2+20*m-16; 5*m^4-14*m^3+28*m-20) and the other solutions are defined by: (X(n); Y(n))= (3*X(n-5)+2*Y(n-5)+p^2; 4*X(n-5)+3*Y(n-5)+2*p^2).
X(n) = 6*X(n-5) - X(n-10) + 2*p^2, and Y(n) = 6*Y(n-5) - Y(n-10) (can be easily proved using X(n) = 3*X(n-5) + 2*Y(n-5) + p^2, and Y(n) = 4*X(n-5) + 3*Y(n-5) + 2*p^2).

Examples

			For p=47 (m=7) the first five (5) consecutive solutions are (0, 2209), (752, 3055), (1820, 4421), (2231, 4969), (3995, 7379).
		

Crossrefs

Cf. A028871 (Primes of the form m^2 - 2).
Solutions x to x^2+(x+p^2)^2=y^2: A118554 (p=7), A207059 (p=17), A309998 (p=23), A331265 (p=31), this sequence (p=47).

Programs

  • Magma
    I:=[0, 752, 1820, 2231, 3995, 6627, 10575, 16511, 18840, 28952]; [n le 10 select I[n] else 6*Self(n-5) - Self(n-10)+4418: n in [1..100]];
    
  • Mathematica
    LinearRecurrence[{1, 0, 0, 0, 6, -6, 0, 0, 0, -1, 1}, {0, 752, 1820, 2231, 3995, 6627, 10575, 16511, 18840, 28952, 44180}, 40] (* Jean-François Alcover, Feb 08 2020 *)
  • PARI
    concat(0, Vec(x^2*(752 + 1068*x + 411*x^2 + 1764*x^3 + 2632*x^4 - 564*x^5 - 472*x^6 - 137*x^7 - 472*x^8 - 564*x^9) / ((1 - x)*(1 - 6*x^5 + x^10)) + O(x^40))) \\ Colin Barker, Feb 04 2020

Formula

a(n) = 6*a(n-5) - a(n-10) + 4418 for n >= 11; a(1)=0, a(2)=752, a(3)=1820, a(4)=2231, a(5)=3995, a(6)=6627, a(7)=10575, a(8)=16511, a(9)=18840, a(10)=28952.
From Colin Barker, Feb 04 2020: (Start)
G.f.: x^2*(752 + 1068*x + 411*x^2 + 1764*x^3 + 2632*x^4 - 564*x^5 - 472*x^6 - 137*x^7 - 472*x^8 - 564*x^9) / ((1 - x)*(1 - 6*x^5 + x^10)).
a(n) = a(n-1) + 6*a(n-5) - 6*a(n-6) - a(n-10) + a(n-11) for n>11.
(End)
Showing 1-9 of 9 results.