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 1-5 of 5 results.

A022086 Fibonacci sequence beginning 0, 3.

Original entry on oeis.org

0, 3, 3, 6, 9, 15, 24, 39, 63, 102, 165, 267, 432, 699, 1131, 1830, 2961, 4791, 7752, 12543, 20295, 32838, 53133, 85971, 139104, 225075, 364179, 589254, 953433, 1542687, 2496120, 4038807, 6534927, 10573734, 17108661, 27682395, 44791056, 72473451, 117264507
Offset: 0

Views

Author

Keywords

Comments

First differences of A111314. - Ross La Haye, May 31 2006
Pisano period lengths: 1, 3, 1, 6, 20, 3, 16, 12, 8, 60, 10, 6, 28, 48, 20, 24, 36, 24, 18, 60, ... . - R. J. Mathar, Aug 10 2012
For n>=6, a(n) is the number of edge covers of the union of two cycles C_r and C_s, r+s=n, with a single common vertex. - Feryal Alayont, Oct 17 2024

References

  • A. T. Benjamin and J. J. Quinn, Proofs that really count: the art of combinatorial proof, M.A.A. 2003, id. 7,17.

Crossrefs

Essentially the same as A097135.
Sequences of the form Fibonacci(n+k) + Fibonacci(n-k) are listed in A280154.
Sequences of the form m*Fibonacci: A000045 (m=1), A006355 (m=2), this sequence (m=3), A022087 (m=4), A022088 (m=5), A022089 (m=6), A022090 (m=7), A022091 (m=8), A022092 (m=8), A022093 (m=10), A022345...A022366 (m=11...32).

Programs

  • Magma
    [3*Fibonacci(n): n in [0..40]]; // Vincenzo Librandi, Dec 31 2016
    
  • Maple
    BB := n->if n=0 then 3; > elif n=1 then 0; > else BB(n-2)+BB(n-1); > fi: > L:=[]: for k from 1 to 34 do L:=[op(L),BB(k)]: od: L; # Zerinvary Lajos, Mar 19 2007
    with (combinat):seq(sum((fibonacci(n,1)),m=1..3),n=0..32); # Zerinvary Lajos, Jun 19 2008
  • Mathematica
    LinearRecurrence[{1, 1}, {0, 3}, 40] (* Arkadiusz Wesolowski, Aug 17 2012 *)
    Table[Fibonacci[n + 4] + Fibonacci[n - 4] - 4 Fibonacci[n], {n, 0, 40}] (* Bruno Berselli, Dec 30 2016 *)
    Table[3 Fibonacci[n], {n, 0, 40}] (* Vincenzo Librandi, Dec 31 2016 *)
  • PARI
    a(n)=3*fibonacci(n) \\ Charles R Greathouse IV, Nov 06 2014
    
  • SageMath
    def A022086(n): return 3*fibonacci(n)
    print([A022086(n) for n in range(41)]) # G. C. Greubel, Apr 10 2025

Formula

a(n) = 3*Fibonacci(n).
a(n) = F(n-2) + F(n+2) for n>1, with F=A000045.
a(n) = round( ((6*phi-3)/5) * phi^n ) for n>2. - Thomas Baruchel, Sep 08 2004
a(n) = A119457(n+1,n-1) for n>1. - Reinhard Zumkeller, May 20 2006
G.f.: 3*x/(1-x-x^2). - Philippe Deléham, Nov 19 2008
a(n) = A187893(n) - 1. - Filip Zaludek, Oct 29 2016
E.g.f.: 6*sinh(sqrt(5)*x/2)*exp(x/2)/sqrt(5). - Ilya Gutkovskiy, Oct 29 2016
a(n) = F(n+4) + F(n-4) - 4*F(n), F = A000045. - Bruno Berselli, Dec 29 2016

A097134 a(n) = 3*Fibonacci(2*n) + 0^n.

Original entry on oeis.org

1, 3, 9, 24, 63, 165, 432, 1131, 2961, 7752, 20295, 53133, 139104, 364179, 953433, 2496120, 6534927, 17108661, 44791056, 117264507, 307002465, 803742888, 2104226199, 5508935709, 14422580928, 37758807075, 98853840297, 258802713816
Offset: 0

Views

Author

Paul Barry, Jul 26 2004

Keywords

Comments

Binomial transform of A097133.
Image of 1/(1-3x) under the mapping g(x)->g(x/(1+x^2)). - Paul Barry, Jan 16 2005

Crossrefs

Cf. A000045.

Programs

Formula

G.f.: (1+x^2)/(1-3*x+x^2).
a(n) = 3*a(n-1) - a(n-2) for n > 2.
a(n) = Sum_{k=0..n} binomial(n, k)*(3*Fibonacci(k)+(-1)^k).
a(n) = A097135(2*n).
a(n) = Sum_{k=0..floor(n/2)} binomial(n-k-1,k)*(-1)^k*3^(n-2*k). - Paul Barry, Jan 16 2005
a(n) = Fibonacci(n+2)^2 - Fibonacci(n-2)^2. - Gary Detlefs, Dec 03 2010
a(n) = Fibonacci(6*n) - 5*Fibonacci(2*n)^3 for n > 0. - Gary Detlefs, Oct 18 2011
E.g.f.: 1 + 6*exp(3*x/2)*sinh(sqrt(5)*x/2)/sqrt(5). - Stefano Spezia, Aug 19 2019

A097136 a(n) = 3*Fibonacci(2*n) + 1.

Original entry on oeis.org

1, 4, 10, 25, 64, 166, 433, 1132, 2962, 7753, 20296, 53134, 139105, 364180, 953434, 2496121, 6534928, 17108662, 44791057, 117264508, 307002466, 803742889, 2104226200, 5508935710, 14422580929, 37758807076, 98853840298, 258802713817, 677554301152
Offset: 0

Views

Author

Paul Barry, Jul 26 2004

Keywords

Comments

Binomial transform of A097135.

Crossrefs

Cf. A000045.

Programs

  • Mathematica
    Table[3*Fibonacci[2n]+1,{n,0,30}] (* or *) LinearRecurrence[{4,-4,1},{1,4,10},30] (* Harvey P. Dale, May 25 2018 *)
  • PARI
    Vec((1-2*x^2)/((1-x)*(1-3*x+x^2)) + O(x^30)) \\ Colin Barker, Nov 02 2016

Formula

G.f.: (1-2*x^2) / ((1-x)*(1-3*x+x^2)).
a(n) = 4*a(n-1) - 4*a(n-2) + a(n-3).
a(n) = 1+3((3+sqrt(5))/2)^n/sqrt(5)-3((3-sqrt(5))/2)^n/sqrt(5).
a(n) = A097132(2*n) = A097133(2*n).

A126714 Dual Wythoff array read along antidiagonals.

Original entry on oeis.org

1, 2, 4, 3, 6, 7, 5, 10, 11, 9, 8, 16, 18, 14, 12, 13, 26, 29, 23, 19, 15, 21, 42, 47, 37, 31, 24, 17, 34, 68, 76, 60, 50, 39, 27, 20, 55, 110, 123, 97, 81, 63, 44, 32, 22, 89, 178, 199, 157, 131, 102, 71, 52, 35, 25, 144, 288, 322, 254, 212, 165, 115, 84, 57, 40, 28
Offset: 1

Views

Author

R. J. Mathar, Feb 12 2007

Keywords

Comments

The dual Wythoff array is the dispersion of the sequence w given by w(n)=2+floor(n*x), where x=(golden ratio), so that w=2+A000201(n). For a discussion of dispersions, see A191426. - Clark Kimberling, Jun 03 2011

Examples

			Array starts
1 2 3 5 8 13 21 34 55 89 144
4 6 10 16 26 42 68 110 178 288 466
7 11 18 29 47 76 123 199 322 521 843
9 14 23 37 60 97 157 254 411 665 1076
12 19 31 50 81 131 212 343 555 898 1453
15 24 39 63 102 165 267 432 699 1131 1830
17 27 44 71 115 186 301 487 788 1275 2063
20 32 52 84 136 220 356 576 932 1508 2440
22 35 57 92 149 241 390 631 1021 1652 2673
25 40 65 105 170 275 445 720 1165 1885 3050
28 45 73 118 191 309 500 809 1309 2118 3427
		

References

  • Clark Kimberling, "Stolarsky Interspersions," Ars Combinatoria 39 (1995) 129-138. See page 135 for the dual Wythoff array and other dual arrays. - Clark Kimberling, Oct 29 2009

Crossrefs

First three rows identical to A035506. First column is A007066. First row is A000045. 2nd row is essentially A006355. 3rd row is essentially A000032. 4th row essentially A000285. 5th row essentially A013655 or A001060. 6th row essentially A022086 or A097135. 7th row essentially A022120. 8th row essentially A022087. 9th row essentially A022130. 10th row essentially A022088. 11th row essentially A022095. 12th row essentially A022089 etc.
Cf. A035513 (Wythoff array).

Programs

  • Maple
    Tn1 := proc(T,nmax,row) local n,r,c,fnd; n := 1; while true do fnd := false; for r from 1 to row do for c from 1 to nmax do if T[r,c] = n then fnd := true; fi; od; if T[r,nmax] < n then RETURN(-1); fi; od; if fnd then n := n+1; else RETURN(n); fi; od; end; Tn2 := proc(T,nmax,row,ai1) local n,r,c,fnd; for r from 1 to row do for c from 1 to nmax do if T[r,c]+1 = ai1 then RETURN(T[r,c+1]+1); fi; od; od; RETURN(-1); end; T := proc(nmax) local a,col,row; a := array(1..nmax,1..nmax); for col from 1 to nmax do a[1,col] := combinat[fibonacci](col+1); od; for row from 2 to nmax do a[row,1] := Tn1(a,nmax,row-1); a[row,2] := Tn2(a,nmax,row-1,a[row,1]); for col from 3 to nmax do a[row,col] := a[row,col-2]+a[row,col-1]; od; od; RETURN(a); end; nmax := 12; a := T(nmax); for d from 1 to nmax do for row from 1 to d do printf("%d, ",a[row,d-row+1]); od; od;
  • Mathematica
    (* program generates the dispersion array T of the complement of increasing sequence f[n] *)
    r = 40; r1 = 12;  (* r=# rows of T, r1=# rows to show *)
    c = 40; c1 = 12;   (* c=# cols of T, c1=# cols to show *)
    x = GoldenRatio; f[n_] := Floor[n*x + 2]
    (* f(n) is complement of column 1 *)
    mex[list_] := NestWhile[#1 + 1 &, 1, Union[list][[#1]] <= #1 &, 1, Length[Union[list]]]
    rows = {NestList[f, 1, c]};
    Do[rows = Append[rows, NestList[f, mex[Flatten[rows]], r]], {r}];
    t[i_, j_] := rows[[i, j]];  (* the array T *)
    TableForm[Table[t[i, j], {i, 1, 10}, {j, 1,10}]]
    (* Dual Wythoff array, A126714 *)
    Flatten[Table[t[k, n - k + 1], {n, 1, c1}, {k, 1, n}]] (* array as a sequence *)
    (* Program by Peter J. C. Moses, Jun 01 2011; added here by Clark Kimberling, Jun 03 2011 *)

A199535 Clark Kimberling's even first column Stolarsky array read by antidiagonals.

Original entry on oeis.org

1, 2, 4, 3, 7, 6, 5, 11, 9, 10, 8, 18, 15, 17, 12, 13, 29, 24, 27, 19, 14, 21, 47, 39, 44, 31, 23, 16, 34, 76, 63, 71, 50, 37, 25, 20, 55, 123, 102, 115, 81, 60, 41, 33, 22, 89, 199, 165, 186, 131, 97, 66, 53, 35, 26, 144, 322, 267, 301, 212, 157, 107, 86, 57, 43, 28
Offset: 1

Views

Author

Casey Mongoven, Nov 07 2011

Keywords

Comments

The rows of the array can be seen to have the form A(n, k) = p(n)*Fibonacci(k) + q(n)*Fibonacci(k+1) where p(n) is the sequence {0, 1, 3, 3, 3, 5, 7, 7, 9, 9, 11, 11, 13, 13, 15, 15, 17, ...}{n >= 1} and q(n) is the sequence {1, 3, 3, 7, 2, 9, 9, 13, 13, 17, 17, 19, 19, 23, 23, 25, ...}{n >= 1}. - G. C. Greubel, Jun 23 2022

Examples

			The even first column stolarsky array (EFC array), northwest corner:
  1......2.....3.....5.....8....13....21....34....55....89...144 ... A000045;
  4......7....11....18....29....47....76...123...199...322...521 ... A000032;
  6......9....15....24....39....63...102...165...267...432...699 ... A022086;
  10....17....27....44....71...115...186...301...487...788..1275 ... A022120;
  12....19....31....50....81...131...212...343...555...898..1453 ... A013655;
  14....23....37....60....97...157...254...411...665..1076..1741 ... A000285;
  16....25....41....66...107...173...280...453...733..1186..1919 ... A022113;
  20....33....53....86...139...225...364...589...953..1542..2495 ... A022096;
  22....35....57....92...149...241...390...631..1021..1652..2673 ... A022130;
Antidiagonal rows (T(n, k)):
   1;
   2,   4;
   3,   7,   6;
   5,  11,   9,  10;
   8,  18,  15,  17, 12;
  13,  29,  24,  27, 19, 14;
  21,  47,  39,  44, 31, 23, 16;
  34,  76,  63,  71, 50, 37, 25, 20;
  55, 123, 102, 115, 81, 60, 41, 33, 22;
		

Crossrefs

Formula

From G. C. Greubel, Jun 23 2022: (Start)
T(n, 1) = A000045(n+1).
T(n, 2) = A000032(n+1), n >= 2.
T(n, 3) = A022086(n) = A097135(n), n >= 3.
T(n, 4) = A022120(n-2), n >= 4.
T(n, 5) = A013655(n-1), n >= 5.
T(n, 6) = A000285(n-2), n >= 6.
T(n, 7) = A022113(n-4), n >= 7.
T(n, 8) = A022096(n-4), n >= 8.
T(n, 9) = A022130(n-6), n >= 9.
T(n, 10) = A022098(n-5), n >= 10.
T(n, 11) = A022095(n-7), n >= 11.
T(n, 12) = A022121(n-8), n >= 12.
T(n, 13) = A022388(n-10), n >= 13.
T(n, 14) = A022122(n-10), n >= 14.
T(n, 15) = A022097(n-10), n >= 15.
T(n, 16) = A022088(n-10), n >= 16.
T(n, 17) = A022390(n-14), n >= 17.
T(n, n) = A199536(n).
T(n, n-1) = A199537(n-1), n >= 2. (End)

Extensions

More terms added by G. C. Greubel, Jun 23 2022
Showing 1-5 of 5 results.