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.

A259823 a(0)=0, a(1)=1, a(n)=min{3 a(k) + 2^(n-k)-1, k=0..(n-1)} for n>=2.

Original entry on oeis.org

0, 1, 3, 6, 10, 16, 24, 33, 45, 61, 79, 103, 130, 162, 198, 246, 300, 364, 436, 517, 613, 721, 849, 993, 1155, 1347, 1563, 1806, 2062, 2350, 2674, 3058, 3490, 3976, 4488, 5064, 5712, 6441, 7209, 8073, 9045, 10069, 11221, 12517, 13975, 15511, 17239, 19183
Offset: 0

Views

Author

Gheorghe Coserea, Jul 05 2015

Keywords

Comments

The sequence of first differences is A003586.

Crossrefs

Programs

  • Haskell
    a259823 n = a259823_list !! n
    a259823_list = scanl (+) 0 a003586_list
    -- Reinhard Zumkeller, Jul 19 2015
  • Mathematica
    a[n_] := a[n] = Min[ Table[ 3*a[k] + 2^(n-k) - 1, {k, 0, n-1}]]; a[0] = 0; Table[a[n], {n, 0, 60}]

Formula

a(n) = min {3*a(k) + 2^(n-k)-1; k < n}.
a(n) = Sum_{i=0..n-1} A003586(i).

A291877 Consider the graph with one central vertex connected to three outer vertices (a star graph). Then, a(n) is the minimum number of moves required to transfer a stack of n discs from the central vertex to an outer vertex, moving discs to adjacent vertices, following the rules of the Towers of Hanoi.

Original entry on oeis.org

1, 4, 7, 14, 23, 32, 47, 68, 93, 120, 153, 198, 255, 318, 399, 480, 579, 700, 835, 1012, 1201, 1428
Offset: 1

Views

Author

Eric M. Schmidt, Sep 04 2017

Keywords

Crossrefs

Cf. A291876.

Extensions

Clarified definition and a(16)-a(18) added by Borut Lužar, Dec 11 2017
a(19)-a(21) by Borut Lužar, Mar 07 2019
a(22) added by Ciril Petr, Jun 22 2021
Showing 1-2 of 2 results.