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 1-3 of 3 results.

A220436 a(n) = A127546(n)^2.

Original entry on oeis.org

4, 36, 196, 1444, 9604, 66564, 454276, 3118756, 21362884, 146458404, 1003749124, 6880038916, 47155859716, 323212716324, 2215328606404, 15184099435684, 104073336269956, 713329336067076, 4889231802533764, 33511293841053604, 229689823620354244, 1574317475335503396, 10790532493690424836
Offset: 0

Views

Author

N. J. A. Sloane, Dec 16 2012

Keywords

References

  • Giacomo Candido, A Relationship Between the Fourth Powers of the Terms of the Fibonacci Series, Scripta Mathematica, Vol. 17, No. 3-4 (1951), p. 230.
  • Shalosh B. Ekhad and Doron Zeilberger, Automatic Counting of Tilings of Skinny Plane Regions, in: Simon R. Blackburn, Stefanie Gerke and Mark Wildon, eds., Surveys in Combinatorics 2013, Cambridge University Press, 2013, pp. 363-378.

Crossrefs

Programs

  • Mathematica
    Table[Total[Fibonacci[Range[n, n + 2]]^2]^2, {n, 0, 22}] (* or *)
    Table[4 (4 ((-1)^(n + 1) LucasL[2 (n + 1)] + LucasL[4 (n + 1)]) + 9)/25, {n, 0, 22}] (* Michael De Vlieger, Feb 18 2017 *)

Formula

Empirical g.f.: -4*(x^4-4*x^3-11*x^2+4*x+1) / ((x-1)*(x^2-7*x+1)*(x^2+3*x+1)). - Colin Barker, Jul 22 2013
a(n) = 4*(4*((-1)^(n + 1)*Lucas(2*(n + 1)) + Lucas(4*(n + 1))) + 9)/25. - Ehren Metcalfe, Feb 18 2017
a(n) = 2 * (F(n)^4 + F(n+1)^4 + F(n+2)^4), where F(n) is the n-th Fibonacci number (A000045) (Candido, 1951). - Amiram Eldar, Jan 11 2022

A059779 A Lucas triangle: T(m,n), m >= n >= 0.

Original entry on oeis.org

2, 1, 1, 3, 2, 3, 4, 3, 3, 4, 7, 5, 6, 5, 7, 11, 8, 9, 9, 8, 11, 18, 13, 15, 14, 15, 13, 18, 29, 21, 24, 23, 23, 24, 21, 29, 47, 34, 39, 37, 38, 37, 39, 34, 47, 76, 55, 63, 60, 61, 61, 60, 63, 55, 76, 123, 89, 102, 97, 99, 98, 99, 97, 102, 89, 123, 199, 144, 165, 157, 160, 159
Offset: 0

Views

Author

N. J. A. Sloane, Feb 22 2001

Keywords

Comments

From Amiram Eldar, May 15 2023: (Start)
Named "Lucas triangle" by Josef (1983), and "Josef's triangle" by Koshy (2007).
The rows of the triangle are the antidiagonals of the array in which the 0th row is T(0, k) = Lucas(k) = A000032(k), the 1st row is T(1, k) = Fibonacci(k+2) = A000045(k+2), and each subsequent row is the sum of the previous 2 rows.
The central elements in the even rows are in A127546, starting from the 2nd row, i.e., the central element of the k-th row, for even k >= 2, is A127546(k/2-1). (End)

Examples

			Triangle starts:
  2;
  1,1;
  3,2,3;
  4,3,3,4;
  ...
		

References

  • Boris A. Bondarenko, Generalized Pascal Triangles and Pyramids (in Russian), FAN, Tashkent, 1990, ISBN 5-648-00738-8.

Crossrefs

Programs

  • Maple
    T := proc(m, n) option remember: if m=0 and n=0 then RETURN(2) fi: if m=1 and n=0 then RETURN(1) fi: if m=1 and n=1 then RETURN(1) fi: if m=2 and n=1 then RETURN(2) fi: if m<=n+1 then RETURN(T(m, m-n)) fi: if mJames Sellers, Feb 22 2001
  • Mathematica
    T[0, k_] := T[0, k] = LucasL[k]; T[1, k_] := T[1, k] = Fibonacci[k + 2]; T[n_, k_] := T[n, k] = T[n - 1, k] + T[n - 2, k]; Table[T[k, n - k], {n, 0, 11}, {k, 0, n}] // Flatten (* Amiram Eldar, May 15 2023 *)

Formula

T(m, n) = T(m-1, n) + T(m-2, n); T(0, 0)=2, T(1, 0)=1, T(1, 1)=1, T(2, 1)=2.

Extensions

More terms from James Sellers, Feb 22 2001

A256661 Rectangular array by antidiagonals: row n shows the numbers k such that R(k) consists of n terms, where R(k) is the minimal alternating Fibonacci representation of k.

Original entry on oeis.org

1, 2, 4, 3, 6, 9, 5, 7, 14, 25, 8, 10, 15, 38, 64, 13, 11, 17, 40, 98, 169, 21, 12, 22, 41, 103, 258, 441, 34, 16, 23, 46, 104, 271, 674, 1156, 55, 18, 24, 59, 106, 273, 708, 1766, 3025, 89, 19, 27, 61, 119, 274, 713, 1855, 4622, 7921, 144, 20, 28, 62, 153
Offset: 1

Views

Author

Clark Kimberling, Apr 08 2015

Keywords

Comments

See A256655 for definitions. Every positive integer occurs exactly once.
(row 1): A000045 (Fibonacci numbers)
(col 1): A007598 (squared Fibonacci numbers)
(col 2): A127546 (conjectured)

Examples

			Northwest corner:
1     2     3     5     8     13    21
4     6     7     10    11    12    62
9     14    15    17    22    23    24
25    38    40    41    46    59    61
64    98    103   104   106   119   153
169   258   271   273   274   279   313
R(1) = 1, in row 1
R(2) = 2, in row 1
R(3) = 3, in row 1
R(4) = 5 - 1, in row 2
R(9) = 13 - 5 + 1, in row 3
R(25) = 34 - 13 + 5 - 1, in row 4
R(64) = 89 - 34 + 13 - 5 + 1, in row 5
		

Crossrefs

Programs

  • Mathematica
    b[n_] = Fibonacci[n]; bb = Table[b[n], {n, 1, 70}];
    h[0] = {1}; h[n_] := Join[h[n - 1], Table[b[n + 2], {k, 1, b[n]}]];
    g = h[23];  r[0] = {0};
    r[n_] := If[MemberQ[bb, n], {n}, Join[{g[[n]]}, -r[g[[n]] - n]]];
    u = Table[Length[r[n]], {n, 1, 6000}];
    TableForm[Table[Flatten[Position[u, k]], {k, 1, 9}]]
Showing 1-3 of 3 results.