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 1-6 of 6 results.

A205594 n such that A205592(n) > n.

Original entry on oeis.org

242, 818, 1841, 2762, 6215, 9323, 13985, 14003, 14012, 20978, 21005, 26243, 29888, 31467, 31468, 31481, 31508, 31529, 31589, 39365, 47201, 47202, 47203, 47222, 47262, 47263, 47294, 47384, 59048, 59156, 59183, 61235, 70802, 70805, 70895, 88572, 88573, 88775, 91853
Offset: 1

Views

Author

Joseph Myers, Jan 29 2012

Keywords

Crossrefs

A205595 A205592(A205594(n)).

Original entry on oeis.org

256, 1024, 2048, 4096, 8192, 16384, 32768, 16384, 16384, 65536, 32768, 32768, 32768, 65536, 65536, 32768, 65536, 32768, 32768, 65536, 131072, 65536, 65536, 65536, 65536, 65536, 65536, 65536, 131072, 65536, 65536, 65536, 262144, 131072, 131072, 131072, 131072, 131072
Offset: 1

Views

Author

Joseph Myers, Jan 29 2012

Keywords

Crossrefs

A205596 Least k such that A205592(k) = 2^n.

Original entry on oeis.org

2, 5, 8, 20, 44, 71, 107, 161, 242, 545, 818, 1841, 2762, 6215, 9323, 13985, 20978, 47201, 70802, 159305, 238958, 358910, 807548, 1814615, 2721923, 4082885, 6124328, 13779557, 20669336, 40222412, 87267041
Offset: 0

Views

Author

Joseph Myers, Jan 29 2012

Keywords

Crossrefs

A205593 a(2) = 0, a(3k) = a(3k+1) = a(2k), a(3k+2) = a(2k+1) + 1 for k >= 1.

Original entry on oeis.org

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

Views

Author

Joseph Myers, Jan 29 2012

Keywords

Crossrefs

Formula

a(n) = log_2(A205592(n)).

A205591 a(1) = 1, a(n) = a(floor((2n-1)/3)) + a(floor(2n/3)) for n > 1.

Original entry on oeis.org

1, 2, 3, 4, 6, 7, 8, 12, 13, 14, 16, 20, 24, 26, 27, 28, 32, 36, 40, 48, 50, 52, 54, 55, 56, 64, 68, 72, 80, 88, 96, 100, 102, 104, 108, 109, 110, 112, 120, 128, 136, 140, 144, 160, 168, 176, 192, 196, 200, 204, 206, 208, 216, 217, 218, 220, 222, 224, 240, 248, 256
Offset: 1

Views

Author

Joseph Myers, Jan 29 2012

Keywords

Comments

In other words, a(1)=1 and then any term is a sum of two earliest possible previous terms (not necessarily distinct), given that each term must be used in summation no more than three times. So a(2)=1+1 (thus 1 gets used twice), a(3)=1+2 (thus 1 gets used for the third and final time, then 2 steps in), and so on. - Ivan Neretin, Jul 09 2015

Crossrefs

A343856 Irregular table read by rows; the first row is [1]; to obtain the next row, replace each odd-indexed term u with (u, u), and each even-indexed term v with (2*v).

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 1, 1, 2, 2, 2, 1, 1, 2, 2, 2, 4, 2, 2, 1, 1, 2, 2, 2, 4, 2, 2, 8, 2, 2, 4, 1, 1, 2, 2, 2, 4, 2, 2, 8, 2, 2, 4, 8, 8, 4, 2, 2, 8, 1, 1, 2, 2, 2, 4, 2, 2, 8, 2, 2, 4, 8, 8, 4, 2, 2, 8, 8, 8, 16, 4, 4, 4, 2, 2, 16, 1, 1, 2, 2, 2, 4, 2, 2, 8, 2, 2, 4, 8, 8, 4, 2, 2, 8, 8, 8, 16, 4, 4, 4, 2, 2, 16, 8, 8, 16, 16, 16, 8, 4, 4, 8, 2, 2, 4, 16, 16
Offset: 1

Views

Author

Rémy Sigrist, May 01 2021

Keywords

Comments

Sequence A061419 and A343857 gives row lengths and partial sums, respectively.
The n-th row sums to 2^(n-1).
This sequence has fractal features.
As with Jim Conant's iterative dissection of a square (A328078), at each iteration, we split in two odd-indexed elements.
This sequence has similarities with A205592: in A205592:
- we start with A205592(1) = 1,
- for k = 1, 2, ...:
if k is odd: append two copies of A205592(k),
if k is even: append 2*A205592(k).

Examples

			Table begins:
1:  [1]
2:  [1, 1]
3:  [1, 1, 2]
4:  [1, 1, 2, 2, 2]
5:  [1, 1, 2, 2, 2, 4, 2, 2]
6:  [1, 1, 2, 2, 2, 4, 2, 2, 8, 2, 2, 4]
7:  [1, 1, 2, 2, 2, 4, 2, 2, 8, 2, 2, 4, 8, 8, 4, 2, 2, 8]
		

Crossrefs

Programs

  • PARI
    { a = r = [1]; for (n=1, 8, i = 0; a=concat(a, r = concat(apply (v -> if (i++%2, [v,v], [2*v]), r)))); print (a) }
    
  • Python
    def auptorow(rows):
      alst, row, newrow = [1], [1], []
      for r in range(2, rows+1):
        for i, v in enumerate(row, start=1): newrow += [v, v] if i%2 else [2*v]
        alst, row, newrow = alst + newrow, newrow, []
      return alst
    print(auptorow(9)) # Michael S. Branicky, May 04 2021
Showing 1-6 of 6 results.