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 1-4 of 4 results.

A288627 Triangle read by rows: T(n,k) = number of step cyclic shifted sequence structures of length n using exactly k different symbols.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 3, 2, 1, 1, 2, 3, 1, 1, 1, 7, 14, 11, 3, 1, 1, 4, 11, 13, 6, 1, 1, 1, 13, 52, 83, 52, 18, 3, 1, 1, 10, 72, 162, 148, 59, 13, 2, 1, 1, 25, 274, 930, 1140, 630, 171, 28, 3, 1, 1, 14, 281, 1369, 2306, 1681, 612, 118, 14, 1, 1
Offset: 1

Views

Author

Andrew Howroyd, Jun 11 2017

Keywords

Comments

See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent. Permuting the symbols will not change the structure.

Examples

			Triangle begins
1;
1,  1;
1,  1,   1;
1,  3,   2,   1;
1,  2,   3,   1,    1;
1,  7,  14,  11,    3,   1;
1,  4,  11,  13,    6,   1,   1;
1, 13,  52,  83,   52,  18,   3,  1;
1, 10,  72, 162,  148,  59,  13,  2, 1;
1, 25, 274, 930, 1140, 630, 171, 28, 3, 1;
...
		

References

  • M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]

Crossrefs

Columns 2-6 are A056434, A056435, A056436, A056437, A056438.
Row sums are A288628.
Partial row sums include A056429, A056430, A056431, A056432, A056433.

Programs

  • PARI
    \\ see A056391 for Polya enumeration functions
    T(n,k) = NonequivalentStructsExactly(CyclicStepShiftPerms(n), k); \\ Andrew Howroyd, Oct 14 2017

A056440 Number of primitive (period n) step cyclic shifted sequence structures using a maximum of three different symbols.

Original entry on oeis.org

1, 1, 2, 4, 5, 18, 15, 60, 80, 293, 295, 2217, 1777, 9763, 20632, 58362, 79553, 600696, 567543, 3671674, 6935728, 23785615, 31017007, 246154210, 282456327, 1357925621, 2615206650, 11358502734
Offset: 1

Views

Author

Keywords

Comments

See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent. Permuting the symbols will not change the structure.

References

  • M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]

Crossrefs

Cf. A056420.

Formula

Sum mu(d)*A056430(n/d) where d divides n.

A056435 Number of step cyclic shifted sequence structures using exactly three different symbols.

Original entry on oeis.org

0, 0, 1, 2, 3, 14, 11, 52, 72, 274, 281, 2155, 1741, 9650, 20456, 58071, 79293, 599452, 566739, 3668218, 6931312, 23776154, 31008623, 246109051, 282422552, 1357819070, 2615067966, 11358104142
Offset: 1

Views

Author

Keywords

Comments

See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent. Permuting the symbols will not change the structure.

References

  • M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]

Crossrefs

Column 3 of A288627.
Cf. A056416.

Formula

A056436 Number of step cyclic shifted sequence structures using exactly four different symbols.

Original entry on oeis.org

0, 0, 0, 1, 1, 11, 13, 83, 162, 930, 1369, 13730, 16421, 124702, 355793, 1356781, 2555043, 25933814, 32931815, 283330733, 720489755, 3308255032, 5763641923, 60874698532, 93543112676, 600086810852
Offset: 1

Views

Author

Keywords

Comments

See A056371 for an explanation of step shifts. Under step cyclic shifts, abcde, bdace, bcdea, cdeab and daceb etc. are equivalent. Permuting the symbols will not change the structure.

References

  • M. R. Nester (1999). Mathematical investigations of some plant interaction designs. PhD Thesis. University of Queensland, Brisbane, Australia. [See A056391 for pdf file of Chap. 2]

Crossrefs

Column 4 of A288627.
Cf. A056417.

Formula

Showing 1-4 of 4 results.