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 1-2 of 2 results.

A194126 -1+A088207.

Original entry on oeis.org

1, 6, 13, 23, 36, 51, 69, 89, 112, 138, 166, 197, 231, 267, 306, 347, 391, 438, 487, 539, 593, 650, 710, 772, 837, 905, 975, 1048, 1123, 1201, 1282, 1365, 1451, 1540, 1631, 1725, 1821, 1920, 2022, 2126, 2233, 2342, 2454, 2569, 2686, 2806, 2929
Offset: 1

Views

Author

Clark Kimberling, Aug 15 2011

Keywords

Comments

A194077 is the natural fractal sequence of A194126.

Crossrefs

Programs

  • Mathematica
    c[k_]:=-1+Sum[Floor[j+j*GoldenRatio],{j,1,k}];
    c=Table[c[k],{k,1,40}]

Formula

a(n)=-1+sum(floor(j+j*r) : 1<=j<=n), where r=(1+sqrt(5))/2, the golden ratio.

A117647 a(2n) = A014445(n), a(2n+1) = A015448(n+1).

Original entry on oeis.org

0, 1, 2, 5, 8, 21, 34, 89, 144, 377, 610, 1597, 2584, 6765, 10946, 28657, 46368, 121393, 196418, 514229, 832040, 2178309, 3524578, 9227465, 14930352, 39088169, 63245986, 165580141, 267914296, 701408733, 1134903170, 2971215073, 4807526976, 12586269025, 20365011074, 53316291173
Offset: 0

Views

Author

Creighton Dement, Apr 10 2006

Keywords

Comments

Because of g.f. in Formula section, numbers k + 1 such that A088207(k)/k is an integer. - Ctibor O. Zizka, Apr 07 2025

Crossrefs

Programs

  • Magma
    I:=[0,1,2,5]; [n le 4 select I[n] else 4*Self(n-2) +Self(n-4): n in [1..41]]; // G. C. Greubel, Jul 12 2021
    
  • Mathematica
    Table[Fibonacci[(6*n+1 -(-1)^n)/4], {n, 0, 40}] (* G. C. Greubel, Jul 12 2021 *)
  • Sage
    [fibonacci((6*n+1-(-1)^n)/4) for n in [0..40]] # G. C. Greubel, Jul 12 2021

Formula

a(n) = A059973(n+2) - A059973(n+1).
G.f.: x*(x+1)^2/(1 -4*x^2 -x^4).
a(n) = Fibonacci((6*n + 1 - (-1)^n)/4) = Fibonacci(A007494(n)). - G. C. Greubel, Jul 12 2021
Showing 1-2 of 2 results.