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 1-6 of 6 results.

A005497 Erroneous version of A210696.

Original entry on oeis.org

1, 2, 5, 16, 48, 164, 599, 1952
Offset: 0

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Author

Keywords

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

A262586 Square array T(n,m) (n>=0, m>=0) read by antidiagonals downwards giving number of rooted triangulations of type [n,m] up to orientation-preserving isomorphisms.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 4, 5, 6, 5, 6, 16, 21, 26, 24, 19, 48, 88, 119, 147, 133, 49, 164, 330, 538, 735, 892, 846, 150, 559, 1302, 2310, 3568, 4830, 5876, 5661, 442, 1952, 5005, 9882, 16500, 24596, 33253, 40490, 39556, 1424, 6872, 19504, 41715, 75387, 120582, 176354, 237336, 290020, 286000, 4522
Offset: 0

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Author

N. J. A. Sloane, Oct 20 2015

Keywords

Examples

			Array begins:
 ==============================================================
 n\k |    0     1      2       3       4        5         6 ...
 ----+---------------------------------------------------------
   0 |    1     1      1       4       6       19        49 ...
   1 |    1     2      5      16      48      164       559 ...
   2 |    1     6     21      88     330     1302      5005 ...
   3 |    5    26    119     538    2310     9882     41715 ...
   4 |   24   147    735    3568   16500    75387    338685 ...
   5 |  133   892   4830   24596  120582   578622   2730728 ...
   6 |  846  5876  33253  176354  900240  4493168  22037055 ...
   7 | 5661 40490 237336 1298732 6849810 35286534 178606610 ...
   ...
The first few antidiagonals are:
  1,
  1,1,
  1,2,1,
  4,5,6,5,
  6,16,21,26,24,
  19,48,88,119,147,133,
  49,164,330,538,735,892,846,
  ...
		

Crossrefs

Columns 0..2 are A002709, A002710, A002711.
Rows 0..3 are A001683, A210696, A005498, A005499.
Antidiagonal sums are A341855.
Cf. A169808 (unoriented), A169809 (achiral).

Programs

  • Maple
    A262586 := proc(n,m)
        BrownG(n,m) ; # procedure in A210696
    end proc:
    for d from 0 to 12 do
        for n from 0 to d do
            printf("%d,",A262586(n,d-n)) ;
        end do:
    end do: # R. J. Mathar, Oct 21 2015
  • Mathematica
    (* See LINKS section. *)
  • PARI
    \\ See Links in A169808 for PARI program file.
    { for(n=0, 7, for(k=0, 7, print1(OrientedTriangs(n,k), ", ")); print) } \\ Andrew Howroyd, Nov 23 2024

Formula

Brown (Eq. 6.3) gives a formula.

A002711 Triangulations of the disk G_{n,2}.

Original entry on oeis.org

1, 5, 21, 119, 735, 4830, 33253, 237336, 1743588, 13114465, 100591491, 784428522, 6204258970, 49675571820, 402013608525, 3284214703056, 27055525967324, 224557688302164, 1876374953765620, 15774315150669075, 133345566025874055, 1132905339504465590, 9669675838370401035
Offset: 0

Views

Author

Keywords

References

  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Column k=2 of A262586.
Cf. A210696.

Programs

Extensions

Extended by Max Alekseyev, Mar 30 2009
a(21) onwards from Andrew Howroyd, Nov 23 2024

A005498 Triangulations of the disk G_{2,n}.

Original entry on oeis.org

1, 6, 21, 88, 330, 1302, 5005, 19504, 75582, 294140, 1144066, 4458192, 17383860, 67866918, 265182525, 1037169760, 4059928950, 15905412468, 62359143990, 244662838160, 960566918220, 3773656396796, 14833897694226, 58343359313568, 229591913401900, 903936171565752, 3560597348629860
Offset: 0

Views

Author

Keywords

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Row n=2 of A262586.

Programs

Extensions

More terms from R. J. Mathar, Mar 30 2012
a(25) onwards from Andrew Howroyd, Nov 23 2024

A005495 Number of triangulations of the disk G_{n,3}.

Original entry on oeis.org

4, 16, 88, 538, 3568, 24596, 176354, 1298732, 9788838, 75190990, 586994548, 4646450800, 37225608048, 301400446752, 2463161448024, 20297411421166, 168503717726980, 1408243135178256, 11840473621942108, 100102553809842544
Offset: 0

Views

Author

Keywords

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Programs

A005499 Triangulations of the disk G_{3,n}.

Original entry on oeis.org

5, 26, 119, 538, 2310, 9882, 41715, 175088, 730626, 3037510, 12584726, 52003792, 214401024, 882233898, 3624161175, 14865947668, 60898934250, 249184153548, 1018532686314, 4159265561360, 16970015555220, 69183689403686, 281844056190294, 1147419353238816, 4668368905854840, 18982659409726792
Offset: 0

Views

Author

Keywords

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Row n=3 of A262586.

Programs

Extensions

a(22) onwards from Andrew Howroyd, Nov 23 2024
Showing 1-6 of 6 results.