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 17 results. Next

A056589 Third column sequence of unsigned triangle A056588.

Original entry on oeis.org

1, 4, 16, 53, 166, 492, 1413, 3960, 10912, 29689, 80026, 214196, 570289, 1512300, 3998160, 10545741, 27766942, 73012060, 191785165, 503378480, 1320425536, 3462057009, 9074076786, 23776857828, 62289901081, 163159711492
Offset: 0

Views

Author

Wolfdieter Lang Jul 10 2000

Keywords

Crossrefs

Formula

a(n)= -A056588(n+2, 2), n >= 0. a(n)= -2^(n+3)+F(n+4)*(F(n+3)+1), F(n)=A000045(n).
G.f.(1-x+x^2)/((1-2*x)*(1+x)*(1-3*x+x^2)*(1-x-x^2))

A056592 Row sums of signed triangle A056588.

Original entry on oeis.org

1, 0, -2, -6, -14, 0, 278, 2520, 15016, 0, -2172632, -53222400, -835765304, 0, 851104689248, 55249242048000, 2288258540319136, 0, -16212819419809777952, -2773508758631170560000, -302332135138133434911104, 0, 14824259801049378686209605248
Offset: 0

Views

Author

Wolfdieter Lang Jul 10 2000

Keywords

Crossrefs

Formula

a(n)= sum(A056588(n, m), m=0..n), n >= 0.

A056593 Row sums of unsigned triangle A056588.

Original entry on oeis.org

1, 2, 4, 10, 32, 132, 692, 4620, 39352, 427572, 5918992, 104375880, 2344751912, 67092113592, 2444702271152, 113425536387240, 6700361921561152, 503909247633965712, 48243317287320644752, 5879293173259041034800
Offset: 0

Views

Author

Wolfdieter Lang Jul 10 2000

Keywords

Crossrefs

Formula

a(n)= sum(((-1)^(floor((m+1)/2)))*A056588(n, m), m=0..n), n >= 0.

A056590 Fourth column sequence of triangle A056588.

Original entry on oeis.org

1, 7, 53, 318, 1784, 9288, 46233, 221859, 1036585, 4742650, 21350264, 94895016, 417562385, 1822824255, 7907350365, 34130697462, 146735898760, 628870859320, 2688466352825, 11470754475675, 48865641344081, 207913415718642
Offset: 0

Views

Author

Wolfdieter Lang Jul 10 2000

Keywords

Crossrefs

Formula

a(n)= A056588(n+3, 3), n >= 0.
a(n)= 3^(n+4)-F(n+5)*2^(n+4)+(F(n+3)-2)*F(n+5)*F(n+4)/2; F(n)=A000045(n) (Fibonacci).
G.f.:(1-3*x+8*x^2-3*x^3-3*x^4-4*x^5)/((1+x)*(1-3*x)*(1+x-x^2)*(1-2*x-4*x^2)*(1-3*x+x^2)*(1-4*x-x^2)).

A056591 Fifth column sequence of triangle A056588.

Original entry on oeis.org

1, 12, 166, 1784, 17840, 163504, 1418549, 11751784, 94002810, 730859800, 5554472496, 41437244784, 304478259625, 2209596042260, 15871463933950, 113044318064744, 799558820643440, 5622796403700080, 39354459839661725
Offset: 0

Views

Author

Wolfdieter Lang Jul 10 2000

Keywords

Crossrefs

Programs

  • Maple
    g:= (72*x^9-142*x^8+276*x^7+473*x^6-112*x^5-78*x^3+46*x^2-8*x+1)/((1-x)*(1+2*x)*(1-5*x)*(1+x-x^2)*(1+3*x+x^2)*(1-3*x-9*x^2)*(1-4*x-x^2)*(1-6*x+4*x^2) *(1-7*x+x^2)):
    S:= series(g,x,21):
    seq(coeff(S,x,i),i=0..20); # Robert Israel, Jul 24 2018

Formula

a(n)= A056588(n+4, 4), n >= 0.
a(n)=5^(n+5)-3^(n+5)*F(n+6)-Fibonomial(n+6, 2)*2^(n+5)+Fibonomial(n+6, 3)+Fibonomial(n+6, 4); F(n)=A000045(n) (Fibonacci); Fibonomial(n, m) := A010048(n, m).
G.f.: (72*x^9-142*x^8+276*x^7+473*x^6-112*x^5-78*x^3+46*x^2-8*x+1)/((1-x)*(1+2*x)*(1-5*x)*(1+x-x^2)*(1+3*x+x^2)*(1-3*x-9*x^2)*(1-4*x-x^2)*(1-6*x+4*x^2) *(1-7*x+x^2)).

A126770 Unsigned version of A056588.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 4, 4, 1, 1, 7, 16, 7, 1, 1, 12, 53, 53, 12, 1, 1, 20, 166, 318, 166, 20, 1, 1, 33, 492, 1784, 1784, 492, 33, 1, 1, 54, 1413, 9288, 17840, 9288, 1413, 54, 1, 1, 88, 3960, 46233, 163504, 163504, 46233, 3960, 88, 1, 1, 143, 10912, 221859, 1418549, 2616064, 1418549, 221859, 10912, 143, 1
Offset: 0

Views

Author

Philippe Deléham, Feb 17 2007

Keywords

Examples

			Triangle begins:
  1;
  1, 1;
  1, 2, 1;
  1, 4, 4, 1;
  1, 7, 16, 7, 1;
  1, 12, 53, 53, 12, 1;
  1, 20, 166, 318, 166, 20, 1;
  1, 33, 492, 1784, 1784, 492, 33, 1;
  1, 54, 1413, 9288, 17840, 9288, 1413, 54, 1;
  1, 88, 3960, 46233, 163504, 163504, 46233, 3960, 88, 1;
  1, 143, 10912, 221859, 1418549, 2616064, 1418549, 221859, 10912, 143, 1;
		

Crossrefs

Column sequences: A000012, A000071, A056589-91; A056593 (Row sums).

Programs

  • Mathematica
    T[n_, 1] := 1; T[n_, n_] := 1; T[n_, k_] := Fibonacci[(n - k + 1)]*T[ n - 1, k - 1] + Fibonacci[k ]*T[n - 1, k];
    Table[T[n, m], {n, 1, 11}, {m, 1, n}] // Flatten (* Roger L. Bagula, Sep 09 2008 *)

Formula

T(0,0)=1, T(n,k)=0 if k<0 or if k>n, T(n,k)=F(n-k+1)*T(n-1,k-1)+F(k+1)*T(n-1,k) where F(n) = A000045(n).

A255492 Sixth diagonal of triangle in A056588.

Original entry on oeis.org

1, 20, 492, 9288, 163504, 2616064, 39369649, 561744656, 7690052788, 101717711304, 1308089742576, 16431681189504, 202396884008657, 2452192780001276, 29299135239719708, 345967823847659992, 4044638027348853616, 46886410125951835648, 539632277597240357409
Offset: 0

Views

Author

N. J. A. Sloane, Mar 06 2015

Keywords

Crossrefs

Cf. A056588.

A056570 Third power of Fibonacci numbers (A000045).

Original entry on oeis.org

0, 1, 1, 8, 27, 125, 512, 2197, 9261, 39304, 166375, 704969, 2985984, 12649337, 53582633, 226981000, 961504803, 4073003173, 17253512704, 73087061741, 309601747125, 1311494070536, 5555577996431, 23533806109393, 99690802348032, 422297015640625
Offset: 0

Views

Author

Wolfdieter Lang, Jul 10 2000

Keywords

Comments

Divisibility sequence; that is, if n divides m, then a(n) divides a(m).
In general, cubing the terms of a Horadam sequence with signature (c,d) will result in a fourth-order recurrence with signature (c^3+2*c*d, c^4*d+3*(c*d)^2+2*d^3, -(c*d)^3-2*c*d^4, -d^6). - Gary Detlefs, Nov 12 2021
a(n+1) is the number of tilings of an n-board (a board with dimensions n X 1) using (1/3,2/3)-fences and third-squares (1/3 X 1 pieces, always placed so that the shorter sides are horizontal). A (w,g)-fence is a tile composed of two w X 1 pieces separated by a gap of width g. a(n+1) also equals the number of tilings of an n-board using (1/6,1/3)-fences and (1/6,5/6)-fences. - Michael A. Allen, Jan 11 2022

Examples

			a(4) = 27 because the fourth Fibonacci number is 3 and 3^3 = 27.
a(5) = 125 because the fifth Fibonacci number is 5 and 5^3 = 125.
		

References

  • D. E. Knuth, The Art of Computer Programming. Addison-Wesley, Reading, MA, 1969, Vol. 1, p. 85, (exercise 1.2.8. Nr. 30) and p. 492 (solution).

Crossrefs

Cf. A346513 (first differences), A005968 (partial sums).
Third row of array A103323.

Programs

Formula

a(n) = A000045(n)^3.
G.f.: x*p(3, x)/q(3, x) with p(3, x) = Sum_{m=0..2} A056588(2, m)*x^m = 1 -2*x -x^2 and q(3, x) = Sum_{m=0..4} A055870(4, m)*x^m = 1 -3*x -6*x^2 +3*x^3 +x^4 = (1+x-x^2)*(1-4*x-x^2) (factorization deduced from Riordan result).
Recursion (cf. Knuth's exercise): 1*a(n) -3*a(n-1) -6*a(n-2) +3*a(n-3) +1*a(n-4) = 0, n >= 4, a(0)=0, a(1)=a(2)=1, a(3)=2^3. See 5th row of signed Fibonomial triangle for coefficients: A055870(4, m), m=0..4
a(n) = (Fibonacci(3n) - 3(-1)^n*Fibonacci(n))/5. - Ralf Stephan, May 14 2004
a(n) and a(n+1) are found as rightmost and leftmost terms (respectively) in M^n * [1 0 0 0] where M = the 4 X 4 upper triangular Pascal's triangle matrix [1 3 3 1 / 1 2 1 0 / 1 1 0 0 / 1 0 0 0]. E.g., Ma(4) = 27, a(5) = 125. M^4 * [1 0 0 0] = [125 75 45 27]; where 75 = A066259(4) and 45 = A066258(3). The characteristic polynomial of M = x^4 - 3x^3 - 6x^2 + 3x + 1. a(n)/a(n-1) of the sequence and companions tend to 2+sqrt(5) = 4.2360679..., an eigenvalue of M and a root of the polynomial. - Gary W. Adamson, Oct 31 2004
From R. J. Mathar, Oct 16 2006: (Start)
Sum_{j=0..n} binomial(n,j)*a(j) = (2^n*A001906(n) + 3*A000045(n))/5.
Sum_{j=0..n} (-1)^j*binomial(n,j)*a(j) = ((-2)^n*A000045(n) - 3*A001906(n))/5. (End)
G.f.: x*(1-2*x-x^2)/((1+x-x^2)*(1-4*x-x^2)). - Colin Barker, Feb 28 2012
a(n) = F(n-2)*F(n+1)^2 + F(n-1)*(-1)^n. - J. M. Bergot, Mar 17 2016
a(n) = ((-3*(1/2*(-1-sqrt(5)))^n-(2-sqrt(5))^n+3*(1/2*(-1+sqrt(5)))^n+(2+sqrt(5))^n)) / (5*sqrt(5)). - Colin Barker, Jun 04 2016
a(n) = F(n-1)*F(n)*F(n+1) + F(n)*(-1)^(n-1). - Tony Foster III, Apr 11 2018
5*a(n) = L(2*n-1)*F(n+2) - L(2*n+1)*F(n-2) - 7*(-1)^n*F(n), where L(n) = A000032(n). - Peter Bala, Nov 12 2019
F(n+1)*F(n)*F(n-1) = 2*Sum_{j=1..n-1} P(j)*a(n-j) for n>0, where Pell number P(n) = A000129(n). - Michael A. Allen, Jan 11 2022

A056572 Fifth power of Fibonacci numbers A000045.

Original entry on oeis.org

0, 1, 1, 32, 243, 3125, 32768, 371293, 4084101, 45435424, 503284375, 5584059449, 61917364224, 686719856393, 7615646045657, 84459630100000, 936668172433707, 10387823949447757, 115202670521319424, 1277617458486664901
Offset: 0

Views

Author

Wolfdieter Lang, Jul 10 2000

Keywords

Comments

Divisibility sequence; that is, if n divides m, then a(n) divides a(m).

References

  • D. E. Knuth, The Art of Computer Programming. Addison-Wesley, Reading, MA, 1969, Vol. 1, p. 85, (exercise 1.2.8. Nr. 30) and p. 492 (solution).

Crossrefs

Fifth row of array A103323.

Programs

Formula

a(n) = F(n)^5, F(n)=A000045(n).
G.f.: x*p(5, x)/q(5, x) with p(5, x) := sum(A056588(4, m)*x^m, m=0..4)= 1-7*x-16*x^2+7*x^3+x^4 and q(5, x) := sum(A055870(6, m)*x^m, m=0..6)= 1-8*x-40*x^2+60*x^3+40*x^4-8*x^5-x^6 = (1-x-x^2)*(1+4*x-x^2)*(1-11*x-x^2) (factorization deduced from Riordan result).
Recursion (cf. Knuth's exercise): sum(A055870(6, m)*a(n-m), m=0..6) = 0, n >= 6; inputs: a(n), n=0..5. a(n) = +8*a(n-1) +40*a(n-2) -60*a(n-3) -40*a(n-4) +8*a(n-5) +a(n-6).
a(n) = (10*F(n) + 5*(-1)^(n+1)*F(3*n) + F(5*n))/25, n >= 0. See the general comment on A111418 regarding the Ozeki reference; here the row 10, 5, 1 of that triangle applies. - Wolfdieter Lang, Aug 25 2012
a(n) = (F(n)^2*(F(3*n)-(-1)^n*3*F(n)))/5. - Gary Detlefs, Jan 07 2013
a(n) = F(n-2)*F(n-1)*F(n)*F(n+1)*F(n+2) + F(n). - Tony Foster III, Apr 11 2018

A056571 Fourth power of Fibonacci numbers A000045.

Original entry on oeis.org

0, 1, 1, 16, 81, 625, 4096, 28561, 194481, 1336336, 9150625, 62742241, 429981696, 2947295521, 20200652641, 138458410000, 949005240561, 6504586067281, 44583076827136, 305577005139121, 2094455819300625, 14355614096087056
Offset: 0

Views

Author

Wolfdieter Lang, Jul 10 2000

Keywords

Comments

Divisibility sequence; that is, if n divides m, then a(n) divides a(m).
a(n+1) is the number of tilings of an n-board (a board with dimensions n X 1) using (1/4,3/4)-fences and quarter-squares (1/4 X 1 pieces, always placed so that the shorter sides are horizontal). A (w,g)-fence is a tile composed of two w X 1 pieces separated by a gap of width g. a(n+1) also equals the number of tilings of an n-board using (1/8,3/8)-fences and (1/8,7/8)-fences. - Michael A. Allen, Jan 11 2022

References

  • A. T. Benjamin and J. J. Quinn, Proofs that really count: the art of combinatorial proof, M.A.A. 2003, id. 31.
  • Donald E. Knuth, The Art of Computer Programming. Addison-Wesley, Reading, MA, 1969, Vol. 1, p. 85, (exercise 1.2.8. Nr. 30) and p. 492 (solution).
  • Hilary I. Okagbue, Muminu O. Adamu, Sheila A. Bishop and Abiodun A. Opanuga, Digit and Iterative Digit Sum of Fibonacci numbers, their identities and powers, International Journal of Applied Engineering Research ISSN 0973-4562 Volume 11, Number 6 (2016) pp. 4623-4627.

Crossrefs

First differences of A005969.
Fourth row of array A103323.

Programs

Formula

a(n) = F(n)^4 = A007598(n)^2, F(n) = A000045(n).
G.f.: x*p(4, x)/q(4, x) with p(4, x) := sum(A056588(3, m)*x^m, m=0..3) = 1 - 4*x - 4*x^2 + x^3 = (1+x)*(1 - 5*x + x^2) and q(4, x) := Sum_{m=0..5} A055870(5, m)*x^m = 1 - 5*x - 15*x^2 + 15*x^3 + 5*x^4 - x^5 = (1-x)*(1 + 3*x + x^2)*(1 - 7*x + x^2) (denominator factorization deduced from Riordan result).
Recursion (cf. Knuth's exercise): 1*a(n) - 5*a(n-1) - 15*a(n-2) + 15*a(n-3) + 5*a(n-4) - 1*a(n-5) = 0, n >= 5; inputs: a(n), n=0..4.
(1/25)*((-1)^n*(2*F(2*n-2) - 6*F(2*n+1)) + 2*F(4*n-1) + F(4*n) + 6). - Ralf Stephan, May 14 2004
a(n) = F(n-2)*F(n-1)*F(n+1)*F(n+2) + 1 = A244855(n)+1.
Sum_{j=0..n} binomial(n,j)*a(j) = (3^n*A005248(n) - 4*(-1)^n*A000032(n) + 6*2^n)/25. Sum_{j=0..n} (-1)^j*binomial(n,j)*a(j) = -5^((n+1)/2-2)*(A001906(n) + 4*A000045(n)) if n odd. - R. J. Mathar, Oct 16 2006
a(n) = (F(n)*F(3n) - 3*F(n)^2*(-1)^n)/5. - Gary Detlefs, Dec 26 2010
Product_{n>=3} (1 - 1/a(n)) = phi^5/12, where phi is the golden ratio (A001622)(Ohtsuka, 2017). - Amiram Eldar, Dec 02 2021
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