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 20 results. Next

A104449 Fibonacci sequence with initial values a(0) = 3 and a(1) = 1.

Original entry on oeis.org

3, 1, 4, 5, 9, 14, 23, 37, 60, 97, 157, 254, 411, 665, 1076, 1741, 2817, 4558, 7375, 11933, 19308, 31241, 50549, 81790, 132339, 214129, 346468, 560597, 907065, 1467662, 2374727, 3842389, 6217116, 10059505, 16276621, 26336126, 42612747, 68948873, 111561620
Offset: 0

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Author

Casey Mongoven, Mar 08 2005

Keywords

Comments

The old name was: The Pibonacci numbers (a Fibonacci-type sequence): each term is the sum of the two previous terms.
The 6th row in the Wythoff array begins with the 6th term of the sequence (14, 23, 37, 60, 97, 157, ...). a(n) = f(n-3) + f(n+2) for the Fibonacci numbers f(n) = f(n-1) + f(n-2); f(0) = 0, f(1) = 1.
(a(2*k), a(2*k+1)) give for k >= 0 the proper positive solutions of one of two families (or classes) of solutions (x, y) of the indefinite binary quadratic form x^2 + x*y - y^2 of discriminant 5 representing 11. The other family of such solutions is given by (x2, y2) = (b(2*k), b(2*k+1)) with b = A013655. See the formula in terms of Chebyshev S polynomials S(n, 3) = A001906(n+1) below, which follows from the fundamental solution (3, 1) by applying positive powers of the automorphic matrix given in a comment in A013655. See also A089270 with the Alfred Brousseau link with D = 11. - Wolfdieter Lang, May 28 2019

References

  • V. E. Hoggatt, Jr., Fibonacci and Lucas Numbers. Houghton, Boston, MA, 1969.

Crossrefs

Cf. Other Fibonacci-type sequences: A000045, A000032, A013655. Other related sequences: A001906, A013655, A089270, A103343, A103344.
Wythoff array: A035513.
Essentially the same as A000285.

Programs

  • GAP
    a:=[3,1];; for n in [3..40] do a[n]:=a[n-1]+a[n-2]; od; a; # G. C. Greubel, May 29 2019
  • Magma
    [Fibonacci(n-1) + Lucas(n): n in [0..40]]; // G. C. Greubel, May 29 2019
    
  • Maple
    a:=n->3*fibonacci(n-1)+fibonacci(n): seq(a(n), n=0..40); # Zerinvary Lajos, Oct 05 2007
  • Mathematica
    LinearRecurrence[{1,1},{3,1},40] (* Harvey P. Dale, May 23 2014 *)
  • PARI
    a(n)=3*fibonacci(n-1)+fibonacci(n) \\ Charles R Greathouse IV, Jun 05 2011
    
  • Sage
    ((3-2*x)/(1-x-x^2)).series(x, 40).coefficients(x, sparse=False) # G. C. Greubel, May 29 2019
    

Formula

a(n) = a(n-1) + a(n-2) with a(0) = 3, a(1) = 1.
a(n) = 3*Fibonacci(n-1) + Fibonacci(n). - Zerinvary Lajos, Oct 05 2007
G.f.: (3-2*x)/(1-x-x^2). - Philippe Deléham, Nov 19 2008
a(n) = ( (3*sqrt(5)-1)*((1+sqrt(5))/2)^n + (3*sqrt(5)+1)*((1-sqrt(5) )/2)^n )/(2*sqrt(5)). - Bogart B. Strauss, Jul 19 2013
Bisection: a(2*k) = 4*S(k-1, 3) - 3*S(k-2, 3), a(2*k+1) = 2*S(k-1, 3) + S(k, 3) for k >= 0, with the Chebyshev S(n, 3) polynomials from A001906(n+1) for n >= -1. - Wolfdieter Lang, May 28 2019
a(n) = Fibonacci(n-1) + Lucas(n). - G. C. Greubel, May 29 2019
a(3n + 4)/a(3n + 1) = continued fraction 4,4,4,...,4,9 (that's n 4's followed by a single 9). - Greg Dresden and Shaoxiong Yuan, Jul 16 2019
E.g.f.: (exp((1/2)*(1 - sqrt(5))*x)*(1 + 3*sqrt(5) + (- 1 + 3*sqrt(5))*exp(sqrt(5)*x)))/(2*sqrt(5)). - Stefano Spezia, Jul 18 2019

Extensions

Name changed by Wolfdieter Lang, Jun 17 2019

A103343 Number of representations of n as a sum of distinct elements of the Fibonacci-type sequence beginning 3, 1, 4, 5, 9, 14, 23, 37, ....

Original entry on oeis.org

1, 1, 0, 1, 2, 2, 1, 1, 2, 3, 2, 0, 2, 3, 3, 2, 1, 3, 4, 3, 1, 2, 3, 4, 3, 0, 3, 5, 4, 2, 2, 4, 5, 3, 0, 3, 4, 4, 3, 1, 4, 6, 5, 2, 3, 5, 6, 4, 0, 4, 6, 5, 3, 2, 5, 6, 4, 1, 3, 4, 5, 4, 0, 4, 7, 6, 3, 3, 6, 8, 5, 0, 5, 7, 6, 4, 2, 6, 8, 6, 2, 4, 6, 7, 5, 0, 5, 8, 6, 3, 3, 6, 7, 4, 0, 4, 5, 5, 4, 1, 5
Offset: 0

Views

Author

Casey Mongoven, Feb 01 2005

Keywords

Crossrefs

Extensions

a(0)=1 corrected by Alois P. Heinz, Sep 16 2015

A219479 Number of representations of n as a sum of distinct elements of the generalized Fibonacci sequence beginning 1, 6, 7, 13, 20, 33, 53, ....

Original entry on oeis.org

1, 1, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 1, 3, 2, 0, 0, 0, 0, 2, 3, 1, 0, 0, 0, 0, 3, 3, 0, 0, 0, 0, 2, 4, 2, 0, 0, 0, 0, 3, 3, 0, 0, 0, 0, 1, 4, 3, 0, 0, 0, 0, 3, 5, 2, 0, 0, 0, 0, 4, 4, 0, 0, 0, 0, 2, 5, 3, 0, 0, 0, 0, 3, 4, 1, 0, 0, 0, 0, 4, 4, 0, 0, 0, 0, 3, 6, 3, 0, 0, 0, 0, 5, 5
Offset: 0

Views

Author

Casey Mongoven, Nov 20 2012

Keywords

References

  • J. Berstel, An Exercise on Fibonacci Representations, RAIRO/Informatique Theorique, Vol. 35, No 6, 2001, pp. 491-498.

Crossrefs

Extensions

a(0)=1 from Alois P. Heinz, Sep 16 2015

A219480 Number of representations of n as a sum of distinct elements of the generalized Fibonacci sequence beginning 1, 7, 8, 15, 23, 38, ....

Original entry on oeis.org

1, 1, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 1, 3, 2, 0, 0, 0, 0, 0, 2, 3, 1, 0, 0, 0, 0, 0, 3, 3, 0, 0, 0, 0, 0, 2, 4, 2, 0, 0, 0, 0, 0, 3, 3, 0, 0, 0, 0, 0, 1, 4, 3, 0, 0, 0, 0, 0, 3, 5, 2, 0, 0, 0, 0, 0, 4, 4, 0, 0, 0, 0, 0, 2, 5, 3, 0, 0, 0, 0, 0, 3, 4, 1, 0, 0, 0, 0, 0, 4, 4, 0
Offset: 0

Views

Author

Casey Mongoven, Nov 20 2012

Keywords

Crossrefs

Extensions

a(0)=1 from Alois P. Heinz, Sep 16 2015

A219481 Number of representations of n as a sum of distinct elements of the generalized Fibonacci sequence beginning 1, 8, 9, 17, 26, ....

Original entry on oeis.org

1, 1, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 0, 1, 3, 2, 0, 0, 0, 0, 0, 0, 2, 3, 1, 0, 0, 0, 0, 0, 0, 3, 3, 0, 0, 0, 0, 0, 0, 2, 4, 2, 0, 0, 0, 0, 0, 0, 3, 3, 0, 0, 0, 0, 0, 0, 1, 4, 3, 0, 0, 0, 0, 0, 0, 3, 5, 2, 0, 0, 0, 0, 0, 0, 4, 4, 0, 0, 0, 0, 0, 0, 2, 5, 3, 0, 0, 0, 0
Offset: 0

Views

Author

Casey Mongoven, Nov 20 2012

Keywords

Crossrefs

Extensions

a(0)=1 from Alois P. Heinz, Sep 16 2015

A219482 Number of representations of n as a sum of distinct elements of the generalized Fibonacci sequence beginning 1, 9, 10, 19, 29, 48, ....

Original entry on oeis.org

1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 0, 0, 1, 3, 2, 0, 0, 0, 0, 0, 0, 0, 2, 3, 1, 0, 0, 0, 0, 0, 0, 0, 3, 3, 0, 0, 0, 0, 0, 0, 0, 2, 4, 2, 0, 0, 0, 0, 0, 0, 0, 3, 3, 0, 0, 0, 0, 0, 0, 0, 1, 4, 3, 0, 0, 0, 0, 0, 0, 0, 3, 5, 2, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 0, 0
Offset: 0

Views

Author

Casey Mongoven, Nov 20 2012

Keywords

Crossrefs

Extensions

a(0)=1 from Alois P. Heinz, Sep 16 2015

A219483 Number of representations of n as a sum of distinct elements of the generalized Fibonacci sequence beginning 2, 7, 9, 16, 25, 41, ....

Original entry on oeis.org

1, 0, 1, 0, 0, 0, 0, 1, 0, 2, 0, 1, 0, 0, 0, 0, 2, 0, 2, 0, 0, 0, 0, 1, 0, 3, 0, 2, 0, 0, 0, 0, 2, 0, 3, 0, 1, 0, 0, 0, 0, 3, 0, 3, 0, 0, 0, 0, 2, 0, 4, 0, 2, 0, 0, 0, 0, 3, 0, 3, 0, 0, 0, 0, 1, 0, 4, 0, 3, 0, 0, 0, 0, 3, 0, 5, 0, 2, 0, 0, 0, 0, 4, 0, 4, 0, 0, 0, 0, 2, 0, 5, 0, 3, 0, 0, 0, 0, 3, 0, 4, 0, 1, 0, 0
Offset: 0

Views

Author

Casey Mongoven, Nov 20 2012

Keywords

Crossrefs

Extensions

a(0)=1 from Alois P. Heinz, Sep 16 2015

A219484 Number of representations of n as a sum of distinct elements of the generalized Fibonacci sequence beginning 2, 9, 11, 20, 31, 51, ....

Original entry on oeis.org

1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 2, 0, 1, 0, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, 0, 0, 0, 0, 1, 0, 3, 0, 2, 0, 0, 0, 0, 0, 0, 2, 0, 3, 0, 1, 0, 0, 0, 0, 0, 0, 3, 0, 3, 0, 0, 0, 0, 0, 0, 2, 0, 4, 0, 2, 0, 0, 0, 0, 0, 0, 3, 0, 3, 0, 0, 0, 0, 0, 0, 1, 0, 4, 0, 3, 0, 0, 0, 0, 0, 0, 3, 0, 5, 0, 2, 0, 0, 0, 0, 0
Offset: 0

Views

Author

Casey Mongoven, Nov 20 2012

Keywords

Crossrefs

Extensions

a(0)=1 from Alois P. Heinz, Sep 16 2015

A219485 Number of representations of n as a sum of distinct elements of the generalized Fibonacci sequence beginning 3, 7, 10, 17, 27, 44, ....

Original entry on oeis.org

1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 2, 0, 0, 1, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0, 1, 0, 0, 3, 0, 0, 2, 0, 0, 0, 2, 0, 0, 3, 0, 0, 1, 0, 0, 0, 3, 0, 0, 3, 0, 0, 0, 2, 0, 0, 4, 0, 0, 2, 0, 0, 0, 3, 0, 0, 3, 0, 0, 0, 1, 0, 0, 4, 0, 0, 3, 0, 0, 0, 3, 0, 0, 5, 0, 0, 2, 0, 0, 0, 4, 0, 0, 4, 0, 0, 0, 2, 0, 0, 5, 0, 0
Offset: 0

Views

Author

Casey Mongoven, Nov 20 2012

Keywords

Crossrefs

Extensions

a(0)=1 from Alois P. Heinz, Sep 16 2015

A219486 Number of representations of n as a sum of distinct elements of the generalized Fibonacci sequence beginning 3, 8, 11, 19, 30, 49, ....

Original entry on oeis.org

1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 2, 0, 0, 1, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0, 0, 1, 0, 0, 3, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 3, 0, 0, 1, 0, 0, 0, 0, 3, 0, 0, 3, 0, 0, 0, 0, 2, 0, 0, 4, 0, 0, 2, 0, 0, 0, 0, 3, 0, 0, 3, 0, 0, 0, 0, 1, 0, 0, 4, 0, 0, 3, 0, 0, 0, 0, 3, 0, 0, 5, 0, 0, 2, 0, 0, 0, 0, 4, 0, 0
Offset: 0

Views

Author

Casey Mongoven, Nov 20 2012

Keywords

Crossrefs

Extensions

a(0)=1 from Alois P. Heinz, Sep 16 2015
Showing 1-10 of 20 results. Next