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: Joshua Xiong

Joshua Xiong's wiki page.

Joshua Xiong has authored 16 sequences. Here are the ten most recent ones:

A241988 The number of P-positions in the Consecutive game with at most three piles, allowing for piles of zero, that are born by generation n.

Original entry on oeis.org

1, 6, 15, 28, 41, 64, 93, 122, 151, 190, 229, 276, 337, 394, 445, 508, 581, 660, 741, 820, 903, 996, 1083, 1170, 1275, 1372, 1467, 1590, 1711, 1848, 1977, 2088, 2213, 2358, 2489, 2648, 2801, 2972, 3133, 3306
Offset: 0

Author

Tanya Khovanova and Joshua Xiong, Aug 10 2014

Keywords

Comments

In the Consecutive game, there are several piles of counters. A player is allowed to take the same positive number of counters from any subset of consecutive piles or any positive number of counters from one pile. The player who cannot move loses.

Examples

			For n = 1 the a(1) = 6 P-positions are (0,0,0), (1,0,1), (0,1,2), (0,2,1), (1,2,0), and (2,1,0).
		

Crossrefs

Cf. A241987 (partial sums), A237686 (Nim), A241984 (Cookie Monster Game), A241986 (At-Most-2-Jars Game).

A241987 The number of P-positions in the Consecutive game with at most three piles, allowing for piles of zero, that are born in generation n.

Original entry on oeis.org

1, 5, 9, 13, 13, 23, 29, 29, 29, 39, 39, 47, 61, 57, 51, 63, 73, 79, 81, 79, 83, 93, 87, 87, 105, 97, 95, 123, 121, 137, 129, 111, 125, 145, 131, 159, 153, 171, 161, 173
Offset: 0

Author

Tanya Khovanova and Joshua Xiong, Aug 10 2014

Keywords

Comments

In the Consecutive game, there are several piles of counters. A player is allowed to take the same positive number of counters from any subset of consecutive piles or any positive number of counters from one pile. The player who cannot move loses.
a(n) is always odd.

Examples

			For n = 1 the a(1) = 5 P-positions are (1,0,1), (0,1,2), (0,2,1), (1,2,0), and (2,1,0).
		

Crossrefs

Cf. A241988 (first differences), A237711 (Nim), A241983 (Cookie Monster Game), A241985 (At-Most-2-Jars Game).

A241986 The number of P-positions in the At-Most-2-Jars game with at most three piles, allowing for piles of zero, that are born by generation n.

Original entry on oeis.org

1, 8, 21, 34, 59, 96, 133, 176, 213, 256, 311, 360, 433, 512, 591, 700, 797, 912, 997, 1094, 1191, 1336, 1457, 1566, 1729, 1880, 2031, 2146, 2267, 2448, 2623, 2834, 3027, 3220, 3431, 3600, 3811, 4082, 4269, 4450
Offset: 0

Author

Tanya Khovanova and Joshua Xiong, Aug 10 2014

Keywords

Comments

In the At-Most-2-Jars game, there are several piles of counters. A player is allowed to take the same positive number of counters from any subset of two piles or any positive number of counters from one pile. The player who cannot move loses.

Examples

			For n = 1 the a(1) = 8 P-positions are (0,0,0), (1,1,1), and permutations of (0,1,2).
		

Crossrefs

Cf. A241985 (partial sums), A237686 (Nim), A241984 (Cookie Monster Game), A241988 (Consecutive Game).

A241985 The number of P-positions in the At-Most-2-Jars game with up to three piles, allowing for piles of zero, that are born in generation n.

Original entry on oeis.org

1, 7, 13, 13, 25, 37, 37, 43, 37, 43, 55, 49, 73, 79, 79, 109, 97, 115, 85, 97, 97, 145, 121, 109, 163, 151, 151, 115, 121, 181, 175, 211, 193, 193, 211, 169, 211, 271, 187, 181
Offset: 0

Author

Tanya Khovanova and Joshua Xiong, Aug 10 2014

Keywords

Comments

In the At-Most-2-Jars game, there are several piles of counters. A player is allowed to take the same positive number of counters from any subset of two piles or any positive number of counters from one pile. The player who cannot move loses.
a(n) is always 1 greater than a multiple of 6.

Examples

			For n = 1 the a(1) = 7 P-positions are (1,1,1) and permutations of (0,1,2).
		

Crossrefs

Cf. A241986 (first differences), A237711 (Nim), A241983 (Cookie Monster Game), A241987 (Consecutive Game).

A241984 The number of P-positions in the Cookie Monster game with at most three piles, allowing for piles of zero, that are born by generation n.

Original entry on oeis.org

1, 7, 19, 37, 55, 82, 127, 166, 232, 316, 385, 463, 547, 634, 706, 805, 922, 1036, 1165, 1294, 1429, 1597, 1735, 1888, 2041, 2203, 2395, 2596, 2749, 2911, 3133, 3337, 3559, 3772, 4009, 4261, 4489, 4723, 4987, 5242
Offset: 0

Author

Tanya Khovanova and Joshua Xiong, Aug 10 2014

Keywords

Comments

In the Cookie Monster game, there are several piles of counters. A player is allowed to take the same positive number of counters from any nonempty subset of the piles. The player who cannot move loses.

Examples

			For n = 1 the a(1) = 7 P-positions are (0,0,0) and (0,1,2), and permutations.
		

Crossrefs

Cf. A241983 (partial sums), A237686 (Nim), A241986 (At-Most-2-Jars Game), A241988 (Consecutive Game).

A241983 The number of P-positions in generation n of the Cookie Monster game with up to three piles, allowing for piles of zero.

Original entry on oeis.org

1, 6, 12, 18, 18, 27, 45, 39, 66, 84, 69, 78, 84, 87, 72, 99, 117, 114, 129, 129, 135, 168, 138, 153, 153, 162, 192, 201, 153, 162, 222, 204, 222, 213, 237, 252, 228, 234, 264, 255
Offset: 0

Author

Tanya Khovanova and Joshua Xiong, Aug 10 2014

Keywords

Examples

			The a(1) = 6 P-positions are (0,1,2) and permutations.
		

A238759 The number of P-positions in the game of Nim with up to five piles, allowing for piles of zero, such that the total number of objects in all piles is 2n.

Original entry on oeis.org

1, 10, 15, 100, 65, 150, 175, 1000, 565, 650, 475, 1500, 925, 1750, 1875, 10000, 5565, 5650, 3475, 6500, 3725, 4750, 3875, 15000, 8425, 9250, 6375, 17500, 10625, 18750, 19375, 100000, 55565, 55650, 33475, 56500, 31725, 34750, 23875, 65000
Offset: 0

Author

Tanya Khovanova and Joshua Xiong, May 02 2014

Keywords

Comments

First differences of A238147.

Examples

			The P-positions with the total of 4 are permutations of (0,0,0,2,2) and (0,1,1,1,1). Therefore, a(2)=15.
		

Crossrefs

Cf. A238147 (partial sums), A048883 (3 piles), A237711 (4 piles), A241523, A241731.

Programs

  • Mathematica
    Table[Length[
      Select[Flatten[
        Table[{n, k, j, i, BitXor[n, k, j, i]}, {n, 0, a}, {k, 0, a}, {j,
          0, a}, {i, 0, a}], 3], Total[#] == a &]], {a, 0, 90, 2}]
    (* Second program: *)
    (* b = A238147 *) b[n_] := b[n] = Which[n <= 1, {1, 11}[[n+1]], OddQ[n], 11 b[(n-1)/2] + 5 b[(n-1)/2 - 1], EvenQ[n], b[(n-2)/2 + 1] + 15 b[(n-2)/2]];
    Join[{1}, Differences[Array[b, 40, 0]]] (* Jean-François Alcover, Dec 14 2018 *)

Formula

a(2n+1) = 10*a(n), a(2n+2) = a(n+1) + 5*a(n).

A238147 The number of P-positions in the game of Nim with up to five piles, allowing for piles of zero, such that the total number of objects in all piles doesn't exceed 2n.

Original entry on oeis.org

1, 11, 26, 126, 191, 341, 516, 1516, 2081, 2731, 3206, 4706, 5631, 7381, 9256, 19256, 24821, 30471, 33946, 40446, 44171, 48921, 52796, 67796, 76221, 85471, 91846, 109346, 119971, 138721, 158096, 258096, 313661, 369311
Offset: 0

Author

Tanya Khovanova and Joshua Xiong, May 02 2014

Keywords

Comments

Partial sums of A238759.

Examples

			There is 1 position (0,0,0,0,0) with a total of zero. There are 10 positions with a total of 2 that are permutations of (0,0,0,1,1). Therefore, a(1)=11.
		

Crossrefs

Cf. A238759 (first differences), A130665 (3 piles), A237686 (4 piles), A241523, A241731.

Programs

  • Mathematica
    Table[Length[
      Select[Flatten[
        Table[{n, k, j, i, BitXor[n, k, j, i]}, {n, 0, a}, {k, 0, a}, {j,
          0, a}, {i, 0, a}], 3], #[[5]] <= a &]], {a, 0, 35}]
    (* Second program: *)
    a[n_] := a[n] = Which[n <= 1, {1, 11}[[n+1]], OddQ[n], 11 a[(n-1)/2] + 5 a[(n-1)/2 - 1], EvenQ[n], a[(n-2)/2 + 1] + 15*a[(n-2)/2]];
    Array[a, 34, 0] (* Jean-François Alcover, Dec 14 2018 *)

Formula

a(2n+1) = 11a(n) + 5a(n-1), a(2n+2) = a(n+1) + 15a(n).

A237711 The number of P-positions in the game of Nim with up to four piles, allowing for piles of zero, such that the total number of objects in all piles is 2n.

Original entry on oeis.org

1, 6, 7, 36, 13, 42, 43, 216, 49, 78, 55, 252, 85, 258, 259, 1296, 265, 294, 127, 468, 133, 330, 307, 1512, 337, 510, 343, 1548, 517, 1554, 1555, 7776, 1561, 1590, 559, 1764, 421, 762, 595, 2808, 601, 798, 463, 1980, 637, 1842, 1819, 9072, 1849
Offset: 0

Author

Tanya Khovanova and Joshua Xiong, May 02 2014

Keywords

Comments

First differences of A237686.

Examples

			The P-positions with the total of 4 are permutations of (0,0,2,2) and (1,1,1,1). Therefore, a(2)=7.
		

Crossrefs

Cf. A237686 (partial sums), A048883 (3 piles), A238759 (5 piles), A241522, A241718.

Programs

  • Mathematica
    Table[Length[
      Select[Flatten[
        Table[{n, k, j, BitXor[n, k, j]}, {n, 0, a}, {k, 0, a}, {j, 0,
          a}], 2], Total[#] == a &]], {a, 0, 100, 2}]

Formula

a(2n+1) = 6a(n), a(2n+2) = a(n+1) + a(n).
G.f.: Product_{k>=0} (1 + 6*x^(2^k) + x^(2^(k+1))). - Ilya Gutkovskiy, Mar 16 2021

A237686 The number of P-positions in the game of Nim with up to four piles, allowing for piles of zero, such that the total number of objects in all piles doesn't exceed 2n.

Original entry on oeis.org

1, 7, 14, 50, 63, 105, 148, 364, 413, 491, 546, 798, 883, 1141, 1400, 2696, 2961, 3255, 3382, 3850, 3983, 4313, 4620, 6132, 6469, 6979, 7322, 8870, 9387, 10941, 12496, 20272, 21833, 23423, 23982, 25746, 26167, 26929, 27524, 30332, 30933
Offset: 0

Author

Tanya Khovanova and Joshua Xiong, May 02 2014

Keywords

Comments

Partial sums of A237711.

Examples

			There is a position (0,0,0,0) with a total of zero. There are 6 positions with a total of 2 that are permutations of (0,0,1,1). Therefore, a(1)=7.
		

Crossrefs

Cf. A237711 (first differences), A130665 (3 piles), A238147 (5 piles), A241522, A241718.

Programs

  • Mathematica
    Table[Length[
      Select[Flatten[
        Table[{n, k, j, BitXor[n, k, j]}, {n, 0, a}, {k, 0, a}, {j, 0,
          a}], 2], Total[#] <= a &]], {a, 0, 100, 2}]

Formula

a(2n+1) = 7a(n) + a(n-1), a(2n+2) = a(n+1) + 7a(n).