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.

User: Ambrosio Valencia-Romero

Ambrosio Valencia-Romero's wiki page.

Ambrosio Valencia-Romero has authored 5 sequences.

A357298 Triangle read by rows where all entries in every even row are 1's and the entries in every odd row alternate between 0 (start/end) and 1.

Original entry on oeis.org

0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1
Offset: 1

Author

Keywords

Comments

Row sums are equal to n for even n and (n-1)/2 for odd n; or A065423(n+1).

Examples

			Triangle begins:
   n\k  0  1  2  3  4  5  6  7  8  9 ...
   1    0;
   2    1, 1;
   3    0, 1, 0;
   4    1, 1, 1, 1;
   5    0, 1, 0, 1, 0;
   6    1, 1, 1, 1, 1, 1;
   7    0, 1, 0, 1, 0, 1, 0;
   8    1, 1, 1, 1, 1, 1, 1, 1;
   9    0, 1, 0, 1, 0, 1, 0, 1, 0;
  10    1, 1, 1, 1, 1, 1, 1, 1, 1, 1;
  ...
Formatted as a symmetric triangle -- regular hexagram pattern with 0's at the centers formed by connecting all 1's:
      .----------------------------------------------.
      |                      k=0   1   2   3   4   5 |
      |-----------------------/---/---/---/---/--./  |
-------                          /   /   /   /   /   |
| n=1 |                     0   /   /   /   /   /|   |
-------                            /   /   /   / | 6 |
|   2 |                   1---1   /   /   /   /  |/  |
-------                    \ /       /   /   /   /   |
|   3 |                 0   1   0   /   /   /   /|   |
-------                    / \         /   /   / | 7 |
|   4 |               1---1---1---1   /   /   /  |/  |
-------                \ /     \ /       /   /   /   |
|   5 |             0   1   0   1   0   /   /   /|   |
-------                / \     / \         /   / | 8 |
|   6 |           1---1---1---1---1---1   /   /  |/  |
-------            \ /     \ /     \ /       /   /   |
|   7 |         0   1   0   1   0   1   0   /   /|   |
-------            / \     / \     / \         / | 9 |
|   8 |       1---1---1---1---1---1---1---1   /   /  |
-------        \ /     \ /     \ /     \ /       /   |
|   9 |     0   1   0   1   0   1   0   1   0   /|   |
-------        / \     / \     / \     / \       | . |
|  10 |   1---1---1---1---1---1---1---1---1---1  | . |
-------                                          | . |
		

Crossrefs

Cf. A358125, A065423 (row sums).

Programs

  • Maple
    T := n -> local k; seq(1/2 + 1/2*(-1)^(n*(k + 1)), k = 0 .. n - 1); # formula 1
    seq(T(n), n=1..16); # print first 16 rows of formula 1.
  • PARI
    T(n,k) = bitnegimply(1,n) || bitand(1,k); \\ Kevin Ryde, Dec 21 2022

Formula

T(n, k) = 1/2 + (1/2)*(-1)^(n*(k+1)), for n >= 1 and 0 <= k <= n-1.
T(n, k) = (2^n - 2^(n-k-1) - 2^k) mod 3, for n >= 1 and 0 <= k <= n-1.
T(n, k) = A358125(n, k) mod 3, for n >= 1 and 0 <= k <= n-1.

A359200 Triangle read by rows: T(n, k) = A358125(n,k)*binomial(n-1, k), 0 <= k <= n-1.

Original entry on oeis.org

0, 1, 1, 3, 8, 3, 7, 30, 30, 7, 15, 88, 144, 88, 15, 31, 230, 520, 520, 230, 31, 63, 564, 1620, 2240, 1620, 564, 63, 127, 1330, 4620, 8120, 8120, 4620, 1330, 127, 255, 3056, 12432, 26432, 33600, 26432, 12432, 3056, 255, 511, 6894, 32112, 79968, 122976, 122976, 79968, 32112, 6894, 511
Offset: 1

Author

Keywords

Examples

			Triangle begins:
   0;
   1,     1;
   3,     8,     3;
   7,    30,    30,      7;
  15,    88,   144,     88,     15;
  31,   230,   520,    520,    230,     31;
  63,   564,  1620,   2240,   1620,    564,     63;
 127,  1330,  4620,   8120,   8120,   4620,   1330,    127;
 255,  3056, 12432,  26432,  33600,  26432,  12432,   3056,   255;
 511,  6894, 32112,  79968, 122976, 122976,  79968,  32112,  6894,   511;
1023, 15340, 80460, 229440, 413280, 499968, 413280, 229440, 80460, 15340, 1023;
...
		

Crossrefs

Row sums give 2*A005061(n-1).

Programs

  • Maple
    T := n -> local k; seq((2^n - 2^(n - k - 1) - 2^k)*binomial(n - 1, k), k = 0 .. n - 1);
    seq(T(n), n = 1 .. 11);
  • Mathematica
    T[n_, k_] := (2^n - 2^(n - k - 1) - 2^k)*Binomial[n - 1, k]; Table[T[n, k], {n, 1, 10}, {k, 0, n - 1}] // Flatten (* Amiram Eldar, Dec 20 2022 *)

Formula

T(n, k) = (2^n - 2^(n-k-1) - 2^k)*binomial(n-1, k), for n >= 1 and 0 <= k <= n-1.

A358125 Triangle read by rows: T(n, k) = 2^n - 2^(n-k-1) - 2^k, 0 <= k <= n-1.

Original entry on oeis.org

0, 1, 1, 3, 4, 3, 7, 10, 10, 7, 15, 22, 24, 22, 15, 31, 46, 52, 52, 46, 31, 63, 94, 108, 112, 108, 94, 63, 127, 190, 220, 232, 232, 220, 190, 127, 255, 382, 444, 472, 480, 472, 444, 382, 255, 511, 766, 892, 952, 976, 976, 952, 892, 766, 511, 1023, 1534, 1788, 1912, 1968, 1984, 1968, 1912, 1788, 1534, 1023
Offset: 1

Author

Keywords

Comments

T(n, k) is the expanded number of player-reduced static games within an n-player two-strategy game scenario in which one player (the "standpoint") faces a specific combination of other players' individual strategies with the possibility of anti-coordination between them -- the total number of such combinations is 2^(n-1). The value of k represents the number of other players who (are expected to) agree on one of the two strategies in S, while the other n-k-1 choose the other strategy; the standpoint player is not included.

Examples

			Triangle begins:
  0;
  1,     1;
  3,     4,    3;
  7,    10,   10,    7;
  15,   22,   24,   22,   15;
  31,   46,   52,   52,   46,   31;
  63,   94,  108,  112,  108,   94,   63;
 127,  190,  220,  232,  232,  220,  190,  127;
 255,  382,  444,  472,  480,  472,  444,  382,  255;
 511,  766,  892,  952,  976,  976,  952,  892,  766,  511;
1023, 1534, 1788, 1912, 1968, 1984, 1968, 1912, 1788, 1534, 1023;
2047, 3070, 3580, 3832, 3952, 4000, 4000, 3952, 3832, 3580, 3070, 2047;
  ...
		

Crossrefs

Column k=0 gives A000225(n-1).
Column k=1 gives A033484(n-2).
Column k=2 gives A053208(n-3).

Programs

  • Maple
    T := n -> seq(2^n - 2^(n - k - 1) - 2^k, k = 0 .. n - 1);
    seq(T(n), n=1..12);
  • Mathematica
    T[n_, k_] := 2^n - 2^(n - k - 1) - 2^k; Table[T[n, k], {n, 1, 11}, {k, 0, n - 1}] // Flatten (* Amiram Eldar, Dec 20 2022 *)

Formula

T(n, k) = 2^n - 2^(n-k-1) - 2^k.
Sum_{k=0..n-1} T(n,k)*binomial(n-1,k) = 2*A005061(n-1)

A350771 Triangle read by rows: T(n, k) = (2^(n-k-1) + 2^k - 2)*binomial(n-1, k), 0 <= k <= n-1.

Original entry on oeis.org

0, 1, 1, 3, 4, 3, 7, 12, 12, 7, 15, 32, 36, 32, 15, 31, 80, 100, 100, 80, 31, 63, 192, 270, 280, 270, 192, 63, 127, 448, 714, 770, 770, 714, 448, 127, 255, 1024, 1848, 2128, 2100, 2128, 1848, 1024, 255, 511, 2304, 4680, 5880, 5796, 5796, 5880, 4680, 2304, 511, 1023, 5120, 11610, 16080, 16380, 15624, 16380, 16080, 11610, 5120, 1023
Offset: 1

Author

Keywords

Comments

The elements in T(n,k) result from the product of each element of A350770(n,k) and binomial(n-1,k).

Examples

			Triangle begins:
     0;
     1,    1;
     3,    4,     3;
     7,   12,    12,     7;
    15,   32,    36,    32,    15;
    31,   80,   100,   100,    80,    31;
    63,  192,   270,   280,   270,   192,    63;
   127,  448,   714,   770,   770,   714,   448,   127;
   255, 1024,  1848,  2128,  2100,  2128,  1848,  1024,   255;
   511, 2304,  4680,  5880,  5796,  5796,  5880,  4680,  2304,  511;
  1023, 5120, 11610, 16080, 16380, 15624, 16380, 16080, 11610, 5120, 1023;
...
		

Crossrefs

Column k=0 gives A000225(n-1).
Row sums give A056182(n-1) = 2*A001047(n-1).

Programs

  • Maple
    T := n -> local k; seq((2^(n - k - 1) + 2^k - 2)*binomial(n - 1, k), k = 0 .. n - 1);
    seq(T(n), n = 1 .. 11);
  • PARI
    T(n, k) = (2^(n-k-1) + 2^k - 2)*binomial(n-1, k) \\ Andrew Howroyd, Jan 05 2024

Formula

T(n, k) = (2^(n-k-1) + 2^k - 2)*binomial(n-1, k).

A350770 Triangle read by rows: T(n, k) = 2^(n-k-1) + 2^k - 2, 0 <= k <= n-1.

Original entry on oeis.org

0, 1, 1, 3, 2, 3, 7, 4, 4, 7, 15, 8, 6, 8, 15, 31, 16, 10, 10, 16, 31, 63, 32, 18, 14, 18, 32, 63, 127, 64, 34, 22, 22, 34, 64, 127, 255, 128, 66, 38, 30, 38, 66, 128, 255, 511, 256, 130, 70, 46, 46, 70, 130, 256, 511, 1023, 512, 258, 134, 78, 62, 78, 134, 258, 512, 1023, 2047, 1024, 514, 262, 142, 94, 94, 142, 262, 514, 1024, 2047
Offset: 1

Author

Keywords

Comments

T(n, k) is the number of player-reduced static games within an n-player two-strategy game scenario in which one player (the "standpoint") faces a specific combination of other players' individual strategies without the possibility of anti-coordination between them -- the total number of such combinations is 2^(n-1). The value of k represents the number of other players who (are expected to) agree on one of the two strategies in S, while the other n-k-1 choose the other strategy; the standpoint player is not included.
The sum of the products of T(n, k) and binomial(n-1,k) for 0 <= k <= n-1 equals 2*A001047(n-1). For instance, for n = 3, T(3, k) returns 3, 2, and 3 and binomial(3-1,k) returns 1, 2, and 1 for k = 0, 1, and 2, respectively. Then 3*1 + 2*2 + 3*1 = 2*A001047(3-1) = 2*5 = 10. Similarly, for n = 4, the result yields 7*1 + 4*3 + 4*3 + 7*1 = 2*A001047(4-1) = 2*19 = 38.

Examples

			Triangle begins:
     0;
     1,    1;
     3,    2,   3;
     7,    4,   4,   7;
    15,    8,   6,   8,  15;
    31,   16,  10,  10,  16, 31;
    63,   32,  18,  14,  18, 32, 63;
   127,   64,  34,  22,  22, 34, 64, 127;
   255,  128,  66,  38,  30, 38, 66, 128, 255;
   511,  256, 130,  70,  46, 46, 70, 130, 256, 511;
  1023,  512, 258, 134,  78, 62, 78, 134, 258, 512, 1023;
  2047, 1024, 514, 262, 142, 94, 94, 142, 262, 514, 1024, 2047;
  ...
		

Crossrefs

Column k=0 gives A000225(n-1).
Row sums give A145654.
Cf. A001047.

Programs

  • Maple
    T := n -> seq(2^(n - k - 1) + 2^k - 2, k = 0 .. n - 1);
    seq(T(n), n=1..12);
  • PARI
    T(n, k) = 2^(n-k-1) + 2^k - 2 \\ Andrew Howroyd, May 06 2023

Formula

T(n, k) = 2^(n-k-1) + 2^k - 2.