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.

A157696 Define k(n) to be the sequence of integers such that k(n)F(n)=F(2n)(Fibonacci sequence) (A000204); in turn define g(n) to be the sequence of integers such that g(n)k(n)=k(3n)(A110391); finally a(n) is the sequence of integers such that a(n)g(n)=g(5n).

Original entry on oeis.org

31, 2521, 97921, 4974481, 226965751, 10783342081, 504420084871, 23735900452321, 1114384154071681, 52364857850613001, 2459808940392975631, 115562692701892638721, 5428914300540041959471, 255044709450472227347881
Offset: 1

Views

Author

Carmine Suriano, Mar 04 2009

Keywords

Comments

Indices 2 of F(i), 3 of k(i) and 5 of g(i) are the minimum integers that provide sequences of integers.

Crossrefs

Programs

Formula

a(n) = A110391(5*n)/A110391(n) = 27*a(n-1) +904*a(n-2) +1660*a(n-3) -1660*a(n-4) -904*a(n-5) -27*a(n-6) +a(n-7). [From R. J. Mathar, Oct 18 2010]

Extensions

a(1) replaced by 31 - R. J. Mathar, Oct 18 2010

A159583 Values of A110391(5n)/A110391(n).

Original entry on oeis.org

1, 31, 2521, 97921, 4974481, 226965751, 10783342081, 504420084871, 23735900452321, 1114384154071681, 52364857850613001, 2459808940392975631, 115562692701892638721, 5428914300540041959471, 255044709450472227347881
Offset: 0

Views

Author

John W. Layman, Apr 16 2009

Keywords

Comments

It appears that from a(2)=2521 onward, this sequence is the same as A157696.

Crossrefs

A153173 a(n) = L(5*n)/L(n) where L(n) = Lucas number A000204(n).

Original entry on oeis.org

11, 41, 341, 2161, 15251, 103361, 711491, 4868641, 33391061, 228811001, 1568437211, 10749853441, 73681573691, 505018447961, 3461454668501, 23725145626561, 162614613425891, 1114577020834241, 7639424866266611
Offset: 1

Views

Author

Artur Jasinski, Dec 20 2008

Keywords

Comments

All numbers in this sequence are congruent to 1 mod 10.

Crossrefs

Programs

  • Magma
    I:=[11, 41, 341, 2161, 15251]; [n le 5 select I[n] else 5*Self(n-1)+15*Self(n-2)-15*Self(n-3)-5*Self(n-4)+Self(n-5): n in [1..30]]; // G. C. Greubel, Dec 21 2017
  • Mathematica
    Table[LucasL[5*n]/LucasL[n], {n, 1, 50}]
    CoefficientList[Series[x*(11-14*x-29*x^2+6*x^3+x^4)/((1-x)*(x^2-7*x+1)*(x^2+3*x+1)), {x,0,50}], x] (* G. C. Greubel, Dec 21 2017 *)
    a[ n_] := 1 + 5*Fibonacci[n]*Fibonacci[3*n]; (* Michael Somos, Apr 23 2022 *)
  • PARI
    {L(n)=fibonacci(n-1)+fibonacci(n+1)}; a(n) = L(5*n)/L(n) \\ Charles R Greathouse IV, Jun 11 2015
    
  • PARI
    my(x='x+O('x^30)); Vec(x*(11-14*x-29*x^2+6*x^3+x^4 )/((1-x)*(x^2-7*x +1)*(x^2+3*x+1))) \\ G. C. Greubel, Dec 21 2017
    
  • PARI
    {a(n) = 1 + 5*fibonacci(n)*fibonacci(3*n)}; /* Michael Somos, Apr 23 2022 */
    

Formula

From R. J. Mathar, Oct 22 2010: (Start)
a(n) = 5*a(n-1) + 15*a(n-2) - 15*a(n-3) - 5*a(n-4) + a(n-5).
G.f.: -x*(11-14*x-29*x^2+6*x^3+x^4)/( (x-1)*(x^2-7*x+1)*(x^2+3*x+1) ).
a(n) = 1 + A056854(n) - (-1)^n*A005248(n). (End)
From Amiram Eldar, Feb 02 2022: (Start)
a(n) = Lucas(2*n)^2 - (-1)^n*Lucas(2*n) - 1 (Carlitz, Problem B-185).
a(n) = (Lucas(2*n) - 3*(-1)^n)^2 + (-1)^n*(5*Fibonacci(n))^2 (Carlitz, Problem B-186). (End)
a(n) = a(-n) = 1 + 10*A085695(n) = 5 + L(n-1)*L(n)^2*L(n+1) for all n in Z. - Michael Somos, Apr 23 2022

A153175 a(n) = L(7*n)/L(n) where L(n) = Lucas number A000204(n).

Original entry on oeis.org

29, 281, 6119, 101521, 1875749, 33281921, 599786069, 10745088481, 192933544679, 3461223997001, 62114818827629, 1114566304366081, 20000347407134669, 358889844987430121, 6440029487834912999, 115561554399692896321
Offset: 1

Views

Author

Artur Jasinski, Dec 20 2008

Keywords

Comments

All numbers in this sequence are:
congruent to 9 mod 10 (iff n is odd),
congruent to 1 mod 10 (iff n is even).

Crossrefs

Cf. A153177, A153179, A153180. [From R. J. Mathar, Oct 22 2010]

Programs

  • Magma
    [Lucas(7*n)/Lucas(n): n in [0..30]]; // G. C. Greubel, Dec 21 2017
  • Mathematica
    Table[LucasL[7*n]/LucasL[n], {n, 1, 50}]
  • PARI
    {lucas(n) = fibonacci(n+1) + fibonacci(n-1)};
    for(n=0,30, print1( lucas(7*n)/lucas(n), ", ")) \\ G. C. Greubel, Dec 21 2017
    

Formula

From R. J. Mathar, Oct 22 2010: (Start)
a(n) = +13*a(n-1) +104*a(n-2) -260*a(n-3) -260*a(n-4) +104*a(n-5) +13*a(n-6) -a(n-7).
G.f.: -x*(-29+96*x+550*x^2-290*x^3-200*x^4+16*x^5+x^6) / ( (1+x)*(x^2-3*x+1)*(x^2-18*x+1)*(x^2+7*x+1) ).
a(n) = A005248(n) +A087215(n) -(-1)^n*A056854(n) - (-1)^n. (End)

A153177 a(n) = L(9*n)/L(n) where L(n) = Lucas number A000204(n).

Original entry on oeis.org

76, 1926, 109801, 4769326, 230701876, 10716675201, 505618944676, 23714405408926, 1114769987764201, 52357935173823126, 2459933168462154076, 115560463558534156801, 5428954301161174383676, 255043991670277234750326
Offset: 1

Views

Author

Artur Jasinski, Dec 20 2008

Keywords

Comments

All numbers in this sequence are:
congruent to 1 mod 100 (iff n is congruent to 0 mod 3),
congruent to 26 mod 100 (iff n is congruent to 2 or 4 mod 6),
congruent to 76 mod 100 (iff n is congruent to 1 or 5 mod 6).

Crossrefs

Programs

  • Magma
    [Lucas(9*n)/Lucas(n): n in [0..30]]; // G. C. Greubel, Dec 21 2017
  • Mathematica
    Table[LucasL[9*n]/LucasL[n], {n, 1, 50}]
    LinearRecurrence[{34,714,-4641,-12376,12376,4641,-714,-34,1},{76,1926,109801,4769326,230701876,10716675201,505618944676,23714405408926,1114769987764201},20] (* Harvey P. Dale, Aug 12 2012 *)
  • PARI
    {lucas(n) = fibonacci(n+1) + fibonacci(n-1)};
    for(n=0,30, print1( lucas(9*n)/lucas(n), ", ")) \\ G. C. Greubel, Dec 21 2017
    

Formula

From R. J. Mathar, Oct 22 2010: (Start)
a(n) = 34*a(n-1) +714*a(n-2) -4641*a(n-3) -12376*a(n-4) +12376*a(n-5) +4641*a(n-6) -714*a(n-7) -34*a(n-8) +a(n-9).
G.f.: -x*(76-658*x-9947*x^2+13644*x^3+26020*x^4-5306*x^5-1372*x^6+42*x^7 +x^8) / ((x-1)*(x^2+18*x+1)*(x^2-47*x+1)*(x^2+3*x+1)*(x^2-7*x+1)).
a(n) = 1-(-1)^n*A087215(n) -(-1)^n*A005248(n) +A056854(n) +A087265(n). (End)

A153179 a(n) = L(11*n)/L(n) where L(n) = A000204(n).

Original entry on oeis.org

199, 13201, 1970299, 224056801, 28374454999, 3450736132801, 426236170575799, 52337681992411201, 6441140796368008699, 792018481913198430001, 97420733208491869044199, 11981539981561372141075201
Offset: 1

Views

Author

Artur Jasinski, Dec 20 2008

Keywords

Comments

All numbers in this sequence are:
congruent to 99 mod 100 (iff n is odd),
congruent to 1 mod 100 (iff n is even).

Crossrefs

Programs

  • Magma
    [Lucas(11*n)/Lucas(n): n in [0..30]]; // G. C. Greubel, Dec 21 2017
  • Mathematica
    Table[LucasL[11*n]/LucasL[n], {n, 1, 50}]
  • PARI
    {lucas(n) = fibonacci(n+1) + fibonacci(n-1)};
    for(n=0,30, print1( lucas(11*n)/lucas(n), ", ")) \\ G. C. Greubel, Dec 21 2017
    

Formula

From R. J. Mathar, Oct 22 2010: (Start)
a(n) = +89*a(n-1) +4895*a(n-2) -83215*a(n-3) -582505*a(n-4) +1514513*a(n-5) +1514513*a(n-6) -582505*a(n-7) -83215*a(n-8) +4895*a(n-9) +89*a(n-10) -a(n-11).
G.f.: -1 -1/(1+x) +(-2-47*x)/(x^2+47*x+1) +(2-3*x)/(x^2-3*x+1) +(-2-7*x)/(x^2+7*x+1) +(2-123*x)/(x^2-123*x+1) +(2-18*x)/(x^2-18*x+1).
a(n) = -(-1)^n -(-1)^n*A087265(n) +A005248(n) -(-1)^n*A056854(n) +A065705(n) +A087215(n). (End)

A153180 a(n) = L(13n)/L(n) where L(n) = Lucas number A000204(n).

Original entry on oeis.org

521, 90481, 35355581, 10525900321, 3489827263001, 1111126318086721, 359316586176453881, 115509240442846111681, 37216910406644366498621, 11980863523543017476802001, 3858153294795970321295258921
Offset: 1

Views

Author

Artur Jasinski, Dec 20 2008

Keywords

Comments

All numbers in this sequence are:
congruent to 1 mod 10
congruent to 1 mod 100 (iff n is congruent to 0 mod 5),Q congruent to 21 mod 100 (iff n is congruent to 1 or 4 mod 5),
congruent to 81 mod 100 (iff n is congruent to 2 or 3 mod 5).Q

Crossrefs

Programs

  • Mathematica
    Table[LucasL[13 n]/LucasL[n], {n, 1, 150}]

Formula

a(n)= +233*a(n-1) +33552*a(n-2) -1493064*a(n-3) -27372840*a(n-4) +186135312*a(n-5) +488605194*a(n-6) -488605194*a(n-7) -186135312*a(n-8) +27372840*a(n-9) +1493064*a(n-10) -33552*a(n-11) -233*a(n-12) +a(n-13). G.f.: -1+ (-2-123*x)/(x^2+123*x+1) +(2-322*x)/(x^2-322*x+1) +(-2-3*x)/(x^2+3*x+1) +(2-7*x)/(x^2-7*x+1) +(2-47*x)/(x^2-47*x+1) -1/(x-1)+ (-2-18*x)/(x^2+18*x+1). [From R. J. Mathar, Oct 22 2010]

A143790 Integer Quotients of Lucas Numbers; a rectangular array by downward antidiagonals.

Original entry on oeis.org

1, 3, 1, 4, 6, 1, 7, 41, 19, 1, 11, 281, 341, 46, 1, 18, 1926, 6119, 2161, 124, 1, 29, 13201, 109801, 101521, 15251, 321, 1, 47, 90481, 1970299, 4769326, 1875749, 103361, 844, 1, 76, 620166, 35355581, 224056801, 230701876, 33281921, 711491, 2206, 1, 123
Offset: 1

Views

Author

Clark Kimberling, Sep 01 2008

Keywords

Comments

Every integer-valued quotient of Lucas numbers (excluding L(0)=2) is in this array.
(Row 1) = A000032 except for a(0)
(Row 2) = A049685
(Row 3) = A049629
(Column 2) = A110391 except for initial terms

Examples

			Q(3,2)=L(9)/L(3)=76/4=19.
		

Crossrefs

Cf. A000032.

Formula

Row 1: L(k)/L(1), where L(k)=A000032(k) = k-th Lucas number, for k>=1;
Row n: L(2nk-n)/L(n) for n>=2, k>=1.
Showing 1-8 of 8 results.