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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A034358 Number of binary [ n,4 ] codes.

Original entry on oeis.org

0, 0, 0, 1, 5, 16, 43, 106, 240, 516, 1060, 2108, 4064, 7641, 14036, 25253, 44560, 77245, 131658, 220883, 365027, 594674, 955649, 1515908, 2374875, 3676632, 5627587, 8520689, 12767557, 18941641, 27834607, 40530902, 58503994, 83741461, 118904892, 167534794, 234309554, 325373538, 448747606
Offset: 1

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Crossrefs

Column k=4 of both A034356 and A076831 (which are the same except for column k=0).
First differences give A034345.

Programs

  • Sage
    # Fripertinger's method to find the g.f. of column k >= 2 of A076831 or A034356 (for small k):
    def A076831col(k, length):
        G1 = PSL(k, GF(2))
        G2 = PSL(k-1, GF(2))
        D1 = G1.cycle_index()
        D2 = G2.cycle_index()
        f1 = sum(i[1]*prod(1/(1-x^j) for j in i[0]) for i in D1)
        f2 = sum(i[1]*prod(1/(1-x^j) for j in i[0]) for i in D2)
        f = (f1 - f2)/(1-x)
        return f.taylor(x, 0, length).list()
    # For instance the Taylor expansion for column k = 4 (this sequence) gives
    print(A076831col(4, 30)) # Petros Hadjicostas, Oct 07 2019

Extensions

More terms from Petros Hadjicostas, Oct 07 2019

A034357 Number of binary [ n,3 ] codes.

Original entry on oeis.org

0, 0, 1, 4, 10, 22, 43, 77, 131, 213, 333, 507, 751, 1088, 1546, 2159, 2967, 4023, 5384, 7122, 9322, 12081, 15512, 19752, 24950, 31283, 38953, 48188, 59244, 72419, 88037, 106469, 128129, 153476, 183019, 217331, 257033
Offset: 1

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Comments

Also, a(n) is the number of orbits of C_2^3 subgroups of C_2^n under automorphisms of C_2^n. Also, a(n) is the number of faithful representations of C_2^3 of dimension n up to equivalence by automorphisms of (C_2^3). - Andrew Rupinski, Jan 20 2011

Crossrefs

Column k=3 of both A034356 and A076831 (which are the same except for column k=0).
First differences give A034344.

Formula

G.f.: (-x^15+2*x^14-x^13+x^12+x^9-x^7+x^4+x^3)/((1-x)^3*(1-x^2)*(1-x^3)^2*(1-x^4)*(1-x^7)).

A034359 Number of binary [ n,5 ] codes.

Original entry on oeis.org

0, 0, 0, 0, 1, 6, 23, 77, 240, 705, 1988, 5468, 14724, 39006, 101818, 261924, 663748, 1655781, 4062110, 9793065, 23186825, 53896597, 122975627, 275449464, 605794093, 1308633243, 2777847319, 5797093774, 11900199553, 24042491094, 47833081481, 93765335118, 181200186060, 345389067067, 649704599010
Offset: 1

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Crossrefs

Column k=5 of both A034356 and A076831 (which are the same except for column k=0).
First differences give A034346.

Extensions

More terms from Joerg Arndt, Oct 09 2019

A034360 Number of binary [ n,6 ] codes.

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 7, 32, 131, 516, 1988, 7664, 29765, 117169, 467266, 1880517, 7588675, 30491836, 121191234, 473940269, 1816579108, 6806904522, 24897540538, 88831250408, 309108741706, 1049278764758, 3476233500031, 11246972937210, 35561409388625, 109967835029368, 332834886787933, 986732945823099
Offset: 1

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Crossrefs

Column k=6 of both A034356 and A076831 (which are the same except for column k=0).
First differences give A034347.

Extensions

More terms from Joerg Arndt, Oct 09 2019

A034361 Number of binary [ n,7 ] codes.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 1, 8, 43, 213, 1060, 5468, 29765, 173035, 1074526, 7059804, 48235007, 336048291, 2345912476, 16193974418, 109563962854, 722594600193, 4631590699334, 28811338570224, 173868030213652
Offset: 1

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Author

Keywords

References

  • H. Fripertinger and A. Kerber, in AAECC-11, Lect. Notes Comp. Sci. 948 (1995), 194-204.

Crossrefs

Column k=7 of both A034356 and A076831 (which are the same except for column k=0).
First differences give A034348.

A034362 Number of binary [ n,8 ] codes.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 1, 9, 56, 333, 2108, 14724, 117169, 1074526, 11249092, 130484439, 1612782351, 20497233072, 260975054461, 3273854883027, 40073904283055, 476142523109291, 5477680380616386, 60959857679340812
Offset: 1

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Author

Keywords

References

  • H. Fripertinger and A. Kerber, in AAECC-11, Lect. Notes Comp. Sci. 948 (1995), 194-204.

Crossrefs

Column k=8 of both A034356 and A076831 (which are the same except for column k=0).
First differences give A034349.

A076836 Number of inequivalent indecomposable binary linear [n,k] codes with no column of zeros of any dimension k <= n.

Original entry on oeis.org

1, 1, 2, 3, 6, 13, 30, 76, 220, 700, 2520, 10503, 51368, 306328, 2313432, 23069977, 314605256, 5991456377, 160321885780, 6008649072476, 313490988938680, 22641945794083024, 2254587340059129076, 308683056074116543631
Offset: 1

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Author

N. J. A. Sloane, Nov 21 2002

Keywords

References

  • D. Slepian, Some further theory of group codes. Bell System Tech. J. 39 1960 1219-1252.

Crossrefs

Row sums of A034254.

Extensions

More terms from Vladeta Jovovic, Nov 27 2008

A034350 Number of indecomposable binary [ n,3 ] codes without 0 columns.

Original entry on oeis.org

0, 0, 0, 1, 2, 5, 10, 18, 31, 51, 79, 121, 177, 254, 356, 490, 661, 882, 1157, 1501, 1926, 2445, 3073, 3834, 4740
Offset: 1

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Author

Keywords

References

  • H. Fripertinger and A. Kerber, in AAECC-11, Lect. Notes Comp. Sci. 948 (1995), 194-204.

Crossrefs

A034351 Number of indecomposable binary [ n,4 ] codes without 0 columns.

Original entry on oeis.org

0, 0, 0, 0, 1, 3, 10, 28, 71, 165, 361, 754, 1503, 2893, 5393, 9773, 17273, 29860, 50557, 84024, 137228, 220542, 349128, 544980, 839453
Offset: 1

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Author

Keywords

References

  • H. Fripertinger and A. Kerber, in AAECC-11, Lect. Notes Comp. Sci. 948 (1995), 194-204.

Crossrefs

A034352 Number of indecomposable binary [ n,5 ] codes without 0 columns.

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 4, 18, 71, 250, 809, 2484, 7240, 20341, 55322, 146237, 376725, 947555, 2328999, 5598888, 13171906, 30342861, 68481058, 151512767, 328820214
Offset: 1

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Author

Keywords

References

  • H. Fripertinger and A. Kerber, in AAECC-11, Lect. Notes Comp. Sci. 948 (1995), 194-204.

Crossrefs

Previous Showing 11-20 of 33 results. Next