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 1-10 of 11 results. Next

A257761 Positive integers whose square is the sum of 23 consecutive squares.

Original entry on oeis.org

92, 138, 4278, 6532, 205252, 313398, 9847818, 15036572, 472490012, 721442058, 22669672758, 34614182212, 1087671802372, 1660759304118, 52185576841098, 79681832415452, 2503820016570332, 3823067196637578, 120131175218534838, 183427543606188292
Offset: 1

Views

Author

Colin Barker, May 07 2015

Keywords

Comments

Positive integers x in the solutions to 2*x^2-46*y^2-1012*y-7590 = 0.

Examples

			92 is in the sequence because 92^2 = 8464 = 7^2+8^2+...+29^2.
		

Crossrefs

Programs

  • Magma
    I:=[92,138,4278,6532]; [n le 4 select I[n] else 48*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, May 11 2015
  • Mathematica
    LinearRecurrence[{0, 48, 0, -1}, {92, 138, 4278, 6532}, 30] (* Vincenzo Librandi, May 11 2015 *)
  • PARI
    Vec(-46*x*(x-1)*(x+2)*(2*x+1)/(x^4-48*x^2+1) + O(x^100))
    

Formula

a(n) = 48*a(n-2)-a(n-4).
G.f.: -46*x*(x-1)*(x+2)*(2*x+1) / (x^4-48*x^2+1).

A257765 Positive integers whose square is the sum of 26 consecutive squares.

Original entry on oeis.org

195, 1599, 2379, 19695, 163059, 242619, 2008695, 16630419, 24744759, 204867195, 1696139679, 2523722799, 20894445195, 172989616839, 257394980739, 2131028542695, 17643244777899, 26251764312579, 217344016909695, 1799437977728859, 2677422564902319
Offset: 1

Views

Author

Colin Barker, May 07 2015

Keywords

Comments

Positive integers x in the solutions to 2*x^2-52*y^2-1300*y-11050 = 0.

Examples

			195 is in the sequence because 195^2 = 38025 = 25^2+26^2+...+50^2.
		

Crossrefs

Programs

  • Magma
    I:=[195,1599,2379,19695,163059,242619 ]; [n le 6 select I[n] else 102*Self(n-3)-Self(n-6): n in [1..30]]; // Vincenzo Librandi, May 11 2015
  • Mathematica
    LinearRecurrence[{0, 0, 102, 0, 0, -1}, {195, 1599, 2379, 19695, 163059, 242619}, 30] (* Vincenzo Librandi, May 11 2015 *)
    Select[Sqrt[#]&/@Total/@Partition[Range[10^6]^2,26,1],IntegerQ] (* The program generates the first 7 terms of the sequence. *) (* Harvey P. Dale, Mar 10 2024 *)
  • PARI
    Vec(-39*x*(x^5+x^4+5*x^3-61*x^2-41*x-5) / (x^6-102*x^3+1) + O(x^100))
    

Formula

a(n) = 102*a(n-3)-a(n-6).
G.f.: -39*x*(x^5+x^4+5*x^3-61*x^2-41*x-5) / (x^6-102*x^3+1).

A257781 Positive integers whose square is the sum of 50 consecutive squares.

Original entry on oeis.org

245, 385, 495, 655, 795, 1055, 1365, 2205, 2855, 3795, 4615, 6135, 7945, 12845, 16635, 22115, 26895, 35755, 46305, 74865, 96955, 128895, 156755, 208395, 269885, 436345, 565095, 751255, 913635, 1214615, 1573005, 2543205, 3293615, 4378635, 5325055, 7079295
Offset: 1

Views

Author

Colin Barker, May 08 2015

Keywords

Comments

Positive integers x in the solutions to 2*x^2-100*y^2-4900*y-80850 = 0.

Examples

			245 is in the sequence because 245^2 = 60025 = 7^2+8^2+...+56^2.
		

Crossrefs

Programs

  • Magma
    I:=[245,385,495,655,795,1055,1365,2205,2855,3795, 4615,6135]; [n le 12 select I[n] else 6*Self(n-6)-Self(n-12): n in [1..40]]; // Vincenzo Librandi, May 11 2015
  • Mathematica
    LinearRecurrence[{0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, -1}, {245, 385, 495, 655, 795, 1055, 1365, 2205, 2855, 3795, 4615, 6135}, 50] (* Vincenzo Librandi, May 11 2015 *)
    Select[Sqrt[Total/@Partition[Range[10^6]^2,50,1]],IntegerQ] (* Harvey P. Dale, Aug 07 2025 *)
  • PARI
    Vec(-5*x*(39*x^11 +31*x^10 +27*x^9 +23*x^8 +21*x^7 +21*x^6 -211*x^5 -159*x^4 -131*x^3 -99*x^2 -77*x -49) / ((x^6 -2*x^3 -1)*(x^6 +2*x^3 -1)) + O(x^100))
    

Formula

a(n) = 6*a(n-6)-a(n-12).
G.f.: -5*x*(39*x^11 +31*x^10 +27*x^9 +23*x^8 +21*x^7 +21*x^6 -211*x^5 -159*x^4 -131*x^3 -99*x^2 -77*x -49) / ((x^6 -2*x^3 -1)*(x^6 +2*x^3 -1)).

A257780 Positive integers whose square is the sum of 47 consecutive squares.

Original entry on oeis.org

3854, 5170, 369890, 496226, 35505586, 47632526, 3408166366, 4572226270, 327148465550, 438886089394, 31402844526434, 42128492355554, 3014345926072114, 4043896380043790, 289345806058396510, 388171923991848286, 27774183035679992846, 37260460806837391666
Offset: 1

Views

Author

Colin Barker, May 08 2015

Keywords

Comments

Positive integers x in the solutions to 2*x^2-94*y^2-4324*y-67022 = 0.

Examples

			3854 is in the sequence because 3854^2 = 14853316 = 539^2+540^2+...+585^2.
		

Crossrefs

Programs

  • Magma
    I:=[3854,5170,369890,496226 ]; [n le 4 select I[n] else 96*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, May 11 2015
  • Mathematica
    LinearRecurrence[{0, 96, 0, -1}, {3854, 5170, 369890, 496226}, 50] (* Vincenzo Librandi, May 11 2015 *)
  • PARI
    Vec(-94*x*(x^3+x^2-55*x-41) / (x^4-96*x^2+1) + O(x^100))
    

Formula

a(n) = 96*a(n-2)-a(n-4).
G.f.: -94*x*(x^3+x^2-55*x-41) / (x^4-96*x^2+1).

A257823 Positive integers whose square is the sum of 59 consecutive squares.

Original entry on oeis.org

413, 531, 8673, 11269, 426511, 554187, 9192849, 11944727, 452101247, 587437689, 9744411267, 12661399351, 479226895309, 622683396153, 10329066750171, 13421071367333, 507980056926293, 660043812484491, 10948801010769993, 14226322987973629, 538458381114975271
Offset: 1

Views

Author

Colin Barker, May 10 2015

Keywords

Comments

Positive integers x in the solutions to 2*x^2-118*y^2-6844*y-133458 = 0.

Examples

			413 is in the sequence because 413^2 = 170569 = 22^2+23^2+...+80^2.
		

Crossrefs

Programs

  • Magma
    I:=[413,531,8673,11269,426511,554187,9192849, 11944727]; [n le 8 select I[n] else 1060*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, May 11 2015
  • Mathematica
    LinearRecurrence[{0, 0, 0, 1060, 0, 0, 0, -1}, {413, 531, 8673, 11269, 426511, 554187, 9192849, 11944727}, 30] (* Vincenzo Librandi, May 11 2015 *)
  • PARI
    Vec(-59*x*(x-1)*(7*x^6+16*x^5+163*x^4+354*x^3+163*x^2+16*x+7) / (x^8-1060*x^4+1) + O(x^100))
    

Formula

a(n) = 1060*a(n-4)-a(n-8).
G.f.: -59*x*(x-1)*(7*x^6+16*x^5+163*x^4+354*x^3+163*x^2+16*x+7) / (x^8-1060*x^4+1).

A257828 Positive integers whose square is the sum of 97 consecutive squares.

Original entry on oeis.org

679, 1545404, 3675742735, 81619738879, 194132514608060, 461744104375531831, 10253011689091642135, 24386783991798773338556, 58003955471481693294113311, 1287975802673112210113634031, 3063449905150311732357259611836, 7286414311424213782299531873117895
Offset: 1

Views

Author

Colin Barker, May 10 2015

Keywords

Comments

Positive integers x in the solutions to 2*x^2-194*y^2-18624*y-599072 = 0.

Examples

			679 is in the sequence because 679^2 = 461041 = 15^2+16^2+...+111^2.
		

Crossrefs

Programs

  • Magma
    I:=[679,1545404,3675742735,81619738879, 194132514608060,461744104375531831]; [n le 6 select I[n] else 125619266*Self(n-3)-Self(n-6): n in [1..20]]; // Vincenzo Librandi, May 11 2015
  • Mathematica
    LinearRecurrence[{0, 0, 125619266, 0, 0, -1}, {679, 1545404, 3675742735, 81619738879, 194132514608060, 461744104375531831}, 30] (* Vincenzo Librandi, May 11 2015 *)
    Rest[CoefficientList[Series[-679x(x-1)(x^4+2277x^3+5415742x^2+ 2277x+1)/ (x^6-125619266x^3+1),{x,0,15}],x]] (* Harvey P. Dale, Aug 02 2021 *)
  • PARI
    Vec(-679*x*(x-1)*(x^4+2277*x^3+5415742*x^2+2277*x+1) / (x^6-125619266*x^3+1) + O(x^100))
    

Formula

a(n) = 125619266*a(n-3)-a(n-6).
G.f.: -679*x*(x-1)*(x^4+2277*x^3+5415742*x^2+2277*x+1) / (x^6-125619266*x^3+1).

A257826 Positive integers whose square is the sum of 88 consecutive squares.

Original entry on oeis.org

2222, 2530, 39358, 55990, 872938, 994598, 15506810, 22059818, 343935350, 391869082, 6109643782, 8691512302, 135509654962, 154395423710, 2407184143298, 3424433787170, 53390460119678, 60831405072658, 948424442815630, 1349218220632678, 21035705777498170
Offset: 1

Views

Author

Colin Barker, May 10 2015

Keywords

Comments

Positive integers x in the solutions to 2*x^2-176*y^2-15312*y-446600 = 0.

Examples

			2222 is in the sequence because 2222^2 = 4937284 = 192^2+193^2+...+279^2.
		

Crossrefs

Programs

  • Magma
    I:=[2222,2530,39358,55990,872938,994598,15506810, 22059818]; [n le 8 select I[n] else 394*Self(n-4)-Self(n-8): n in [1..40]]; // Vincenzo Librandi, May 11 2015
  • Mathematica
    LinearRecurrence[{0, 0, 0, 394, 0, 0, 0, -1}, {2222, 2530, 39358, 55990, 872938, 994598, 15506810, 22059818}, 40] (* Vincenzo Librandi, May 11 2015 *)
  • PARI
    Vec(-22*x*(11*x^7+11*x^6+101*x^5+115*x^4-2545*x^3-1789*x^2-115*x-101) / (x^8-394*x^4+1) + O(x^100))
    

Formula

a(n) = 394*a(n-4)-a(n-8).
G.f.: -22*x*(11*x^7+11*x^6+101*x^5+115*x^4-2545*x^3-1789*x^2-115*x-101) / (x^8-394*x^4+1).

A269449 The first of 33 consecutive positive integers the sum of the squares of which is a square.

Original entry on oeis.org

7, 27, 60, 181, 227, 612, 1085, 1985, 3492, 9047, 11161, 28860, 50607, 91987, 161276, 416685, 513883, 1327652, 2327541, 4230121, 7415908, 19159167, 23628161, 61043836, 107016983, 194494283, 340971196, 880905701, 1086382227, 2806689508, 4920454381, 8942507601
Offset: 1

Views

Author

Colin Barker, Feb 27 2016

Keywords

Comments

Positive integers y in the solutions to 2*x^2-66*y^2-2112*y-22880 = 0.
All sequences of this type (i.e. sequences with fixed offset k, and a discernible pattern: k=0...32 for this sequence, k=0..1 for A001652, k=0...10 for A106521) can be extended using a formula such as x(n) = a*x(n-p) - x(n-2p) + b, where a and b are various constants, and p is the period of the series. Alternatively 'p' can be considered the number of concurrent series. - Daniel Mondot, Aug 08 2016
Numbers x such that 11440+33*x*(32+x)is a square. - Harvey P. Dale, Oct 18 2020

Examples

			7 is in the sequence because sum(k=7, 39, k^2) = 20449 = 143^2.
		

Crossrefs

Programs

  • Mathematica
    Rest@ CoefficientList[Series[x (7 + 20 x + 33 x^2 + 121 x^3 + 46 x^4 + 385 x^5 + 151 x^6 - 20 x^7 - 11 x^8 - 11 x^9 - 2 x^10 - 11 x^11 - 4 x^12)/((1 - x) (1 - 46 x^6 + x^12)), {x, 0, 32}], x] (* Michael De Vlieger, Aug 08 2016 *)
    LinearRecurrence[{1,0,0,0,0,46,-46,0,0,0,0,-1,1},{7,27,60,181,227,612,1085,1985,3492,9047,11161,28860,50607},50] (* Harvey P. Dale, Oct 18 2020 *)
  • PARI
    Vec(x*(7 +20*x +33*x^2 +121*x^3 +46*x^4 +385*x^5 +151*x^6 -20*x^7 -11*x^8 -11*x^9 -2*x^10 -11*x^11 -4*x^12) / ((1 -x)*(1 -46*x^6 +x^12)) + O(x^40))

Formula

G.f.: x*(7 +20*x +33*x^2 +121*x^3 +46*x^4 +385*x^5 +151*x^6 -20*x^7 -11*x^8 -11*x^9 -2*x^10 -11*x^11 -4*x^12) / ((1 -x)*(1 -46*x^6 +x^12)).
a(1)=7, a(2)=27, a(3)=60, a(4)=181, a(5)=227, a(6)=612, a(7)=1085, a(8)=1985, a(9)=3492, a(10)=9047, a(11)=11161, a(12)=28860, a(n)=46*a(n-6)-a(n-12)+704. - Daniel Mondot, Aug 08 2016

A257824 Positive integers whose square is the sum of 73 consecutive squares.

Original entry on oeis.org

4088, 23360, 1582640, 9047912, 18642443912, 106578370640, 7220791811360, 41281080400088, 85056113063608088, 486263602888235360, 32944848197744794640, 188344846763231651912, 388068345740467131839912, 2218576715650261475158640, 150310804012507009263599360
Offset: 1

Views

Author

Colin Barker, May 10 2015

Keywords

Comments

Positive integers x in the solutions to 2*x^2-146*y^2-10512*y-254040 = 0.

Examples

			4088 is in the sequence because 4088^2 = 16711744 = 442^2+443^2+...+514^2.
		

Crossrefs

Programs

  • Magma
    I:=[4088,23360,1582640,9047912,18642443912, 106578370640,7220791811360,41281080400088]; [n le 8 select I[n] else 4562498*Self(n-4)-Self(n-8): n in [1..20]]; // Vincenzo Librandi, May 11 2015
  • Mathematica
    LinearRecurrence[{0, 0, 0, 4562498, 0, 0, 0, -1}, {4088, 23360, 1582640, 9047912, 18642443912, 106578370640, 7220791811360, 41281080400088}, 40] (* Vincenzo Librandi, May 11 2015 *)
  • PARI
    Vec(-584*x*(x-1)*(7*x^6+47*x^5+2757*x^4+18250*x^3+2757*x^2+47*x+7) / ((x^4-2136*x^2-1)*(x^4+2136*x^2-1)) + O(x^100))
    

Formula

a(n) = 4562498*a(n-4)-a(n-8).
G.f.: -584*x*(x-1)*(7*x^6+47*x^5+2757*x^4+18250*x^3+2757*x^2+47*x+7) / ((x^4-2136*x^2-1)*(x^4+2136*x^2-1)).

A257825 Positive integers whose square is the sum of 74 consecutive squares.

Original entry on oeis.org

2257, 2849, 21941, 27713, 604765, 763865, 16669573, 21054961, 162316669, 205018517, 4474051285, 5651073085, 123321498797, 155764598629, 1200818695321, 1516726961053, 33099030801665, 41806637918965, 912332431430633, 1152346479602381, 8883656545668089
Offset: 1

Views

Author

Colin Barker, May 10 2015

Keywords

Comments

Positive integers x in the solutions to 2*x^2-148*y^2-10804*y-264698 = 0.

Examples

			2257 is in the sequence because 2257^2 = 5094049 = 225^2+226^2+...+298^2.
		

Crossrefs

Programs

  • Magma
    I:=[2257,2849,21941,27713,604765,763865,16669573, 21054961,162316669,205018517,4474051285,5651073085]; [n le 12 select I[n] else 7398*Self(n-6)-Self(n-12): n in [1..40]]; // Vincenzo Librandi, May 11 2015
  • Mathematica
     LinearRecurrence[{0, 0, 0, 0, 0, 7398, 0, 0, 0, 0, 0, -1}, {2257, 2849, 21941, 27713, 604765, 763865, 16669573, 21054961, 162316669, 205018517, 4474051285, 5651073085}, 40] (* Vincenzo Librandi, May 11 2015 *)
  • PARI
    Vec(-37*x*(5*x^11+5*x^10+61*x^9+77*x^8+593*x^7+749*x^6-20645*x^5-16345*x^4-749*x^3-593*x^2-77*x-61) / ((x^6-86*x^3-1)*(x^6+86*x^3-1)) + O(x^100))
    

Formula

a(n) = 7398*a(n-6)-a(n-12).
G.f.: -37*x*(5*x^11+5*x^10+61*x^9+77*x^8+593*x^7+749*x^6-20645*x^5-16345*x^4-749*x^3-593*x^2-77*x-61) / ((x^6-86*x^3-1)*(x^6+86*x^3-1)).
Showing 1-10 of 11 results. Next