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.

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A355056 Number of asymmetric multidimensional n-ominoes with cell centers determining n-3 space.

Original entry on oeis.org

5, 46, 275, 1283, 5281, 19607, 68476, 227196, 727780, 2263148, 6881482, 20529511, 60312548, 174870492, 501443277, 1424142358, 4011274417, 11216074419, 31160837273, 86078096135, 236568911194, 647181951619
Offset: 5

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Author

Robert A. Russell, Jun 16 2022

Keywords

Comments

Multidimensional polyominoes are connected sets of cells of regular tilings with Schläfli symbols {oo}, {4,4}, {4,3,4}, {4,3,3,4}, etc. Each tile is a regular orthotope (hypercube). An asymmetric polyomino has a symmetry group of order 1.

Examples

			a(5)=5 as there are exactly five asymmetric pentominoes in 2-space.
		

Crossrefs

Cf. A355052 (oriented), A355053 (unoriented), A355054 (chiral), A355055 (achiral), A191092 (fixed), A004111 (rooted asymmetric).
Other dimensions: A036366 (n-2), A000220 (n-1), A355051 (orthoplex).

Programs

  • Mathematica
    sa[n_, k_] := sa[n, k] = a[n+1-k, 1] + If[n < 2 k, 0, -sa[n-k, k]];
    a[1, 1] := 1; a[n_, 1] := a[n, 1] = Sum[a[i, 1] sa[n-1, i] i, {i, 1, n-1}]/(n-1);
    a[n_, k_] := a[n, k] = Sum[a[i, 1] a[n-i, k-1], {i, 1, n-1}];
    nmax = 30; A[x_] := Sum[a[i, 1] x^i, {i, 0, nmax}]
    Drop[CoefficientList[Series[(4 A[x]^4 + 37 A[x]^5 + 12 A[x]^6 - 6 A[x]^3 A[x^2] - 10 A[x]^4 A[x^2] - 4 A[x^2]^2 - 17 A[x] A[x^2]^2 - 2 A[x^2]^3 + 2 A[x] A[x^4]) / 8 + (24 A[x]^5 + 515 A[x]^6 + 325 A[x]^7 + 24 A[x]^8 - 48 A[x]^4 A[x^2] - 96 A[x]^5 A[x^2] - 24 A[x]^6 A[x^2] - 21 A[x]^2 A[x^2]^2 + 21 A[x]^3 A[x^2]^2 - 14 A[x^2]^3 + 8 A[x] A[x^2]^3 + 6 A[x]^2 A[x^2]^3 + 4 A[x^3]^2 - 4 A[x] A[x^3]^2 + 24 A[x^2] A[x^4] - 18 A[x] A[x^2] A[x^4] - 6 A[x]^2 A[x^2] A[x^4] - 4 A[x^6] + 4 A[x] A[x^6]) / (24 (1-A[x])) + A[x]^5 (2 A[x] + 67 A[x]^2 + 46 A[x]^3 + 6 A[x]^4 - 3 A[x^2] - 6 A[x] A[x^2] - 2 A[x]^2 A[x^2]) / (2 (1-A[x])^2) - A[x^2] (2 A[x]^2 A[x^2] + 6 A[x]^3 A[x^2] + 2 A[x]^4 A[x^2] + 13 A[x^2]^2 + 31 A[x] A[x^2]^2 + 2 A[x]^2 A[x^2]^2 + 15 A[x^2]^3 + 5 A[x] A[x^2]^3 - 3 A[x^4] - 5 A[x] A[x^4] - 3 A[x^2] A[x^4] - A[x] A[x^2] A[x^4]) / (4 (1-A[x^2])) + A[x]^6 (4 A[x] + 153 A[x]^2 + 75 A[x]^3 + 12 A[x]^4 - 3 A[x^2] - 3 A[x] A[x^2]) / (6 (1-A[x])^3) - A[x]^2 A[x^2]^2 (2 A[x] + 7 A[x]^2 + 5 A[x]^3 + A[x^2] - A[x] A[x^2]) / (2 (1-A[x]) (1-A[x^2])) + A[x] A[x^3]^2 / (1-A[x^3]) / 3 + A[x]^9 (21 + 4 A[x]) / (2 (1-A[x])^4) - A[x]^5 (3 + 2 A[x]) A[x^2]^2 / ((1-A[x])^2 (1-A[x^2])) - A[x^2]^4 (5 + 7 A[x] + 3 A[x^2] + A[x] A[x^2]) / (1-A[x^2])^2 + A[x] A[x^4]^2 / (2 (1-A[x^4])) + 3 A[x]^10 / (2 (1-A[x])^5) - A[x]^6 A[x^2]^2 / ((1-A[x])^3 (1-A[x^2])) - 2 (1 + A[x]) A[x^2]^5 / (1-A[x^2])^3 + 3 (1 + A[x]) A[x^2] A[x^4]^2 / (2 (1-A[x^2]) (1-A[x^4])), {x,0,nmax}], x], 5]

Formula

G.f.: (4 A(x)^4 + 37 A(x)^5 + 12 A(x)^6 - 6 A(x)^3 A(x^2) - 10 A(x)^4 A(x^2) - 4 A(x^2)^2 - 17 A(x) A(x^2)^2 - 2 A(x^2)^3 + 2 A(x) A(x^4)) / 8 + (24 A(x)^5 + 515 A(x)^6 + 325 A(x)^7 + 24 A(x)^8 - 48 A(x)^4 A(x^2) - 96 A(x)^5 A(x^2) - 24 A(x)^6 A(x^2) - 21 A(x)^2 A(x^2)^2 + 21 A(x)^3 A(x^2)^2 - 14 A(x^2)^3 + 8 A(x) A(x^2)^3 + 6 A(x)^2 A(x^2)^3 + 4 A(x^3)^2 - 4 A(x) A(x^3)^2 + 24 A(x^2) A(x^4) - 18 A(x) A(x^2) A(x^4) - 6 A(x)^2 A(x^2) A(x^4) - 4 A(x^6) + 4 A(x) A(x^6)) / (24 (1-A(x))) + A(x)^5 (2 A(x) + 67 A(x)^2 + 46 A(x)^3 + 6 A(x)^4 - 3 A(x^2) - 6 A(x) A(x^2) - 2 A(x)^2 A(x^2)) / (2 (1-A(x))^2) - A(x^2) (2 A(x)^2 A(x^2) + 6 A(x)^3 A(x^2) + 2 A(x)^4 A(x^2) + 13 A(x^2)^2 + 31 A(x) A(x^2)^2 + 2 A(x)^2 A(x^2)^2 + 15 A(x^2)^3 + 5 A(x) A(x^2)^3 - 3 A(x^4) - 5 A(x) A(x^4) - 3 A(x^2) A(x^4) - A(x) A(x^2) A(x^4)) / (4 (1-A(x^2))) + A(x)^6 (4 A(x) + 153 A(x)^2 + 75 A(x)^3 + 12 A(x)^4 - 3 A(x^2) - 3 A(x) A(x^2)) / (6 (1-A(x))^3) - A(x)^2 A(x^2)^2 (2 A(x) + 7 A(x)^2 + 5 A(x)^3 + A(x^2) - A(x) A(x^2)) / (2 (1-A(x)) (1-A(x^2))) + A(x) A(x^3)^2 / (1-A(x^3)) / 3 + A(x)^9 (21 + 4 A(x)) / (2 (1-A(x))^4) - A(x)^5 (3 + 2 A(x)) A(x^2)^2 / ((1-A(x))^2 (1-A(x^2))) - A(x^2)^4 (5 + 7 A(x) + 3 A(x^2) + A(x) A(x^2)) / (1-A(x^2))^2 + A(x) A(x^4)^2 / (2 (1-A(x^4))) + 3 A(x)^10 / (2 (1-A(x))^5) - A(x)^6 A(x^2)^2 / ((1-A(x))^3 (1-A(x^2))) - 2 (1 + A(x)) A(x^2)^5 / (1-A(x^2))^3 + 3 (1 + A(x)) A(x^2) A(x^4)^2 / (2 (1-A(x^2)) (1-A(x^4))) where A(x) is the generating function for rooted identity trees with n nodes in A004111.

A036369 Number of asymmetric orthoplex n-ominoes in n-2 space.

Original entry on oeis.org

0, 0, 2, 10, 33, 101, 277, 754, 1972, 5134, 13145, 33563, 85048, 215075, 541887, 1363376, 3423537, 8588521, 21522243, 53898911, 134895022, 337467395, 843924068, 2109897826, 5273789335, 13180026621, 32934865984
Offset: 4

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Author

Keywords

Comments

Orthoplex polyominoes are multidimensional polyominoes that do not extend more than two units along any axis.

Examples

			a(6)=4 because there are 2 asymmetric hexominoes in 2^4 space.
		

Crossrefs

Programs

  • Mathematica
    sa[ n_, k_ ] := sa[ n, k ]=a[ n+1-k, 1 ]+If[ n<2k, 0, -sa[ n-k, k ] ]; a[ 1, 1 ] := 1;
    a[ n_, 1 ] := a[ n, 1 ]=Sum[ a[ i, 1 ]sa[ n-1, i ]i, {i, 1, n-1} ]/(n-1);
    a[ n_, k_ ] := a[ n, k ]=Sum[ a[ i, 1 ]a[ n-i, k-1 ], {i, 1, n-1} ];
    Table[ a[ i, 4 ]/8+Sum[ a[ i, j ], {j, 5, i} ]/2-If[ OddQ[ i ], 0, a[ i/2, 2 ]/8
    -If[ OddQ[ i/2 ], 0, a[ i/4, 1 ]/4 ]+Sum[ a[ i/2, j ], {j, 3, i/2} ]/2 ]
    -Sum[ a[ j, 1 ]a[ i-2j, 2 ]/4+Sum[ If[ OddQ[ k ], a[ j,
    (k-1)/2 ]a[ i-2j, 1 ], 0 ], {k, 5, i} ]/2, {j, 1, (i-1)/2} ], {i, 4, 30} ]

Formula

G.f.: (A^2(x)-A(x^2))^2/8 - A^2(x^2)/4 + A(x^4)/4 + A^5(x)/(2-2A(x)) - (A(x)+A(x^2))*A^2(x^2)/(2-2A(x^2)) where A(x) is the generating function for rooted identity trees with n nodes in A004111.
Showing 1-2 of 2 results.