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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A056413 Number of step cyclic shifted sequences using a maximum of five different symbols.

Original entry on oeis.org

5, 15, 35, 120, 201, 1505, 2015, 14070, 37085, 246753, 445515, 5205790, 7832185, 72703645, 254689657, 1196213445, 2805046965, 35322811755, 55770979195, 596439735024, 1892294578755, 10837223014665, 23559159229935, 310484619147940, 596046508875701, 4776013513099405, 15330413466776835, 110874578286500410
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.

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

Row 5 of A285548.
Cf. A002729.

Programs

  • Mathematica
    M[j_, L_] := Module[{m = 1}, While[Sum[ j^i, {i, 0, m - 1}] ~Mod~ L != 0, m++]; m]; c[j_, t_, n_] := Sum[ 1/M[j, n / GCD[n, u*(j - 1) + t] ], {u, 0, n - 1} ]; CB[n_, k_] = If [n == 1, k, 1/(n*EulerPhi[n]) * Sum[ If[1 == GCD[n, j], k^c[j, t, n], 0] , {t, 0, n-1}, {j, 1, n-1}]]; Table[ Print[ cb = CB[n, 5]]; cb, {n, 1, 28}] (* Jean-François Alcover, Dec 04 2015, after Joerg Arndt *)
  • PARI
    \\ see p.3 of the Dokovic et al. reference
    M(j,  L)={my(m=1); while ( sum(i=0, m-1, j^i) % L != 0, m+=1 ); m; }
    c(j, t, n)=sum(u=0,n-1, 1/M(j, n / gcd(n, u*(j-1)+t) ) );
    CB(n, k)=if (n==1,k, 1/(n*eulerphi(n)) * sum(t=0,n-1, sum(j=1,n-1, if(1==gcd(n,j), k^c(j,t,n), 0) ) ) );
    for(n=1, 66, print1(CB(n,5),", "));
    \\ Joerg Arndt, Aug 27 2014

Formula

Refer to Titsworth or slight "simplification" in Nester.

Extensions

Added more terms, Joerg Arndt, Aug 27 2014

A056374 Number of step shifted (decimated) sequences using a maximum of five different symbols.

Original entry on oeis.org

5, 25, 75, 375, 825, 8125, 13175, 103125, 327125, 2445625, 4884435, 61640625, 101732425, 1017323125, 3816215625, 19104609375, 47683838325, 635787765625, 1059638680675, 11924780390625, 39736963221875, 238418603522125, 541860418146375
Offset: 1

Views

Author

Keywords

Comments

See A056371 for an explanation of step shifts.

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. A056413.
A row or column of A132191.

Programs

  • Mathematica
    a[m_, n_] := (1/EulerPhi[n])*Sum[If[GCD[k, n] == 1, m^DivisorSum[n, EulerPhi[#]/MultiplicativeOrder[k, #] &], 0], {k, 1, n}]; Table[a[5, n], {n, 1, 23}] (* Jean-François Alcover, Dec 04 2015 *)

Formula

The cycle index is implicit in Titsworth.
Sequences A056372-A056375 fit a general formula, implemented in PARI/GP as follows: { a(m,n) = sum(k=1, n, if(gcd(k, n)==1, m^sumdiv(n, d, eulerphi(d)/znorder(Mod(k, d))), 0); ) / eulerphi(n) }. - Max Alekseyev, Nov 08 2007

Extensions

More terms from Max Alekseyev, Nov 08 2007

A056414 Number of step cyclic shifted sequences using a maximum of six different symbols.

Original entry on oeis.org

6, 21, 56, 231, 462, 4291, 6966, 57561, 188866, 1519035, 3302922, 45921281, 83747286, 933081411, 3920355712, 22075451286, 62230996506, 940379310731, 1781757016326, 22856965214727, 87052415641136, 598280600648031, 1560731765058606, 24680195365765751, 56860576713326910, 546736312124316741, 2105947271634851386
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.

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

Row 6 of A285548.
Cf. A002729.

Programs

  • Mathematica
    M[j_, L_] := Module[{m = 1}, While[Sum[ j^i, {i, 0, m - 1}] ~Mod~ L != 0, m++]; m]; c[j_, t_, n_] := Sum[ 1/M[j, n / GCD[n, u*(j - 1) + t] ], {u, 0, n - 1}]; CB[n_, k_] = If[n == 1, k, 1/(n*EulerPhi[n]) * Sum[ If[1 == GCD[n, j], k^c[j, t, n], 0], {t, 0, n-1}, {j, 1, n-1}]]; Table[ Print[ cb = CB[n, 6]]; cb, {n, 1, 27}] (* Jean-François Alcover, Dec 04 2015, after Joerg Arndt *)
  • PARI
    \\ see p.3 of the Dokovic et al. reference
    M(j,  L)={my(m=1); while ( sum(i=0, m-1, j^i) % L != 0, m+=1 ); m; }
    c(j, t, n)=sum(u=0,n-1, 1/M(j, n / gcd(n, u*(j-1)+t) ) );
    CB(n, k)=if (n==1,k, 1/(n*eulerphi(n)) * sum(t=0,n-1, sum(j=1,n-1, if(1==gcd(n,j), k^c(j,t,n), 0) ) ) );
    for(n=1, 66, print1(CB(n,6),", "));
    \\ Joerg Arndt, Aug 27 2014

Formula

Refer to Titsworth or slight "simplification" in Nester.

Extensions

Added more terms, Joerg Arndt, Aug 27 2014

A056376 Number of step shifted (decimated) sequences using exactly two different symbols.

Original entry on oeis.org

0, 2, 4, 10, 10, 38, 26, 94, 102, 278, 214, 1246, 702, 2798, 4342, 8926, 8230, 44222, 29202, 136030, 176750, 419870, 381490, 2150398, 1678254, 5593998, 7461166, 22553406, 19175158, 134391038, 71585134
Offset: 1

Views

Author

Keywords

Comments

See A056371 for an explanation of step shifts.

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. A056371.

Formula

A056371(n)-2.

A056392 Number of step shifted (decimated) sequence structures using a maximum of three different symbols.

Original entry on oeis.org

1, 2, 4, 10, 14, 70, 68, 332, 577, 2510, 2980, 23372, 22218, 133150, 300964, 909382, 1345634, 10767202, 10762820, 72957100, 145362932, 523029526, 713213956, 5893709440, 7060765733, 35303782550
Offset: 1

Views

Author

Keywords

Comments

See A056371 for an explanation of step shifts. 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

Formula

Use de Bruijn's generalization of Polya's enumeration theorem as discussed in reference.
a(n) = Sum_{k=1..3} A288620(n, k). - Andrew Howroyd, Jun 13 2017

A056393 Number of step shifted (decimated) sequence structures using a maximum of four different symbols.

Original entry on oeis.org

1, 2, 4, 11, 17, 107, 131, 811, 1893, 11107, 17599, 179371, 233449, 1866057, 5603787, 22469291, 44744047, 477262537, 636308685, 5732457131, 15272176697, 73301054891, 133274359129, 1466413263531
Offset: 1

Views

Author

Keywords

Comments

See A056371 for an explanation of step shifts. 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

Formula

Use de Bruijn's generalization of Polya's enumeration theorem as discussed in reference.
a(n) = Sum_{k=1..4} A288620(n, k). - Andrew Howroyd, Jun 13 2017

A056394 Number of step shifted (decimated) sequence structures using a maximum of five different symbols.

Original entry on oeis.org

1, 2, 4, 11, 18, 116, 157, 1110, 3076, 21808, 42335, 528612, 859502, 8547036, 31968397, 159716545, 398048506, 5303680564, 8835749347, 99411986634, 331215914028, 1987084129352, 4515860983385, 62095481040014
Offset: 1

Views

Author

Keywords

Comments

See A056371 for an explanation of step shifts. 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. A056374.

Formula

Use de Bruijn's generalization of Polya's enumeration theorem as discussed in reference.

A056429 Number of step cyclic shifted sequence structures using a maximum of two different symbols.

Original entry on oeis.org

1, 2, 2, 4, 3, 8, 5, 14, 11, 26, 15, 88, 37, 130, 184, 357, 261, 1346, 805, 3760, 4434, 9758, 8385, 47462, 33781, 108330, 138767, 408376, 331185, 2251816, 1155735
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

Formula

Use de Bruijn's generalization of Polya's enumeration theorem as discussed in reference.
a(n) = A288627(n, 2) + 1. - Andrew Howroyd, Jun 13 2017

A056430 Number of step cyclic shifted sequence structures using a maximum of three different symbols.

Original entry on oeis.org

1, 2, 3, 6, 6, 22, 16, 66, 83, 300, 296, 2243, 1778, 9780, 20640, 58428, 79554, 600798, 567544, 3671978, 6935746, 23785912, 31017008, 246156513, 282456333, 1357927400, 2615206733, 11358512518
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

Formula

Use de Bruijn's generalization of Polya's enumeration theorem as discussed in reference.
a(n) = Sum_{k=1..3} A288627(n, k). - Andrew Howroyd, Jun 13 2017

A056431 Number of step cyclic shifted sequence structures using a maximum of four different symbols.

Original entry on oeis.org

1, 2, 3, 7, 7, 33, 29, 149, 245, 1230, 1665, 15973, 18199, 134482, 376433, 1415209, 2634597, 26534612, 33499359, 287002711, 727425501, 3332040944, 5794658931, 61120855045, 93825569009, 601444738252
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

Formula

Use de Bruijn's generalization of Polya's enumeration theorem as discussed in reference.
a(n) = Sum_{k=1..4} A288627(n, k). - Andrew Howroyd, Jun 13 2017
Previous Showing 11-20 of 86 results. Next