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.

A255813 Numbers of words on {0,1,2,3} having no isolated zeros.

Original entry on oeis.org

1, 3, 10, 34, 115, 388, 1309, 4417, 14905, 50296, 169720, 572707, 1932556, 6521263, 22005505, 74255899, 250570870, 845532298, 2853184279, 9627852832, 32488455385, 109629815881, 369937455865, 1248325741972, 4212380047936
Offset: 0

Views

Author

Milan Janjic, Mar 07 2015

Keywords

Crossrefs

Programs

  • Mathematica
    RecurrenceTable[{a[0] == 1, a[1] == 3,  a[2]== 10, a[n] == 4 a[n - 1] - 3 a[n - 2] + 3 a[n - 3]}, a[n], {n, 0, 25}]
    LinearRecurrence[{4, -3, 3}, {1, 3, 10}, 100] (* G. C. Greubel, Jun 02 2016 *)

Formula

a(n+3) = 4*a(n+2) - 3*a(n+1)+ 3*a(n) with n>=0, a(0) = 1, a(1) = 3, a(2) = 10.
G.f.: (-1 + x - x^2)/(-1 + 4*x - 3*x^2 + 3*x^3). - R. J. Mathar, Nov 07 2015

A255814 Numbers of words on {0,1,2,3,4,} having no isolated zeros.

Original entry on oeis.org

1, 4, 17, 73, 313, 1341, 5745, 24613, 105449, 451773, 1935521, 8292309, 35526553, 152205613, 652091089, 2793739205, 11969154121, 51279178141, 219694231041, 941231059125, 4032495084025, 17276328107789, 74016584439345, 317107590101669
Offset: 0

Views

Author

Milan Janjic, Mar 07 2015

Keywords

Crossrefs

Programs

  • Magma
    I:=[1,4,17]; [n le 3 select I[n] else 5*Self(n-1)-4*Self(n-2)+4*Self(n-3): n in [1..30]]; // Vincenzo Librandi, Feb 26 2018
  • Mathematica
    RecurrenceTable[{a[0] == 1, a[1] == 4,  a[2]== 17, a[n] == 5 a[n - 1] - 4 a[n - 2] + 4 a[n - 3]}, a[n], {n, 0, 23}]
    LinearRecurrence[{5, -4, 4}, {1, 4, 17}, 100] (* G. C. Greubel, Jun 02 2016 *)
    CoefficientList[Series[(-1 + x - x^2) / (-1 + 5 x -4 x^2 + 4 x^3), {x, 0, 33}], x] (* Vincenzo Librandi, Feb 26 2018 *)

Formula

a(n+3) = 5*a(n+2) - 4*a(n+1)+ 4*a(n) with n>=0, a(0) = 1, a(1) = 4, a(2) = 17.
G.f.: (-1 + x - x^2)/(-1 + 5*x - 4*x^2 + 4*x^3). - R. J. Mathar, Nov 07 2015

A255815 Numbers of words on {0,1,2,3,4,5} having no isolated zeros.

Original entry on oeis.org

1, 5, 26, 136, 711, 3716, 19421, 101501, 530481, 2772486, 14490016, 75730071, 395792776, 2068556381, 10811024761, 56502330541, 295301641346, 1543353319176, 8066123361031, 42156481777036, 220325040452941, 1151498450637621
Offset: 0

Views

Author

Milan Janjic, Mar 07 2015

Keywords

Crossrefs

Programs

  • Mathematica
    RecurrenceTable[{a[0] == 1, a[1] == 5,  a[2]== 26, a[n] == 6 a[n - 1] - 5 a[n - 2] + 5 a[n - 3]}, a[n], {n, 0, 21}]
    LinearRecurrence[{6, -5, 5}, {1, 5, 26}, 100] (* G. C. Greubel, Jun 02 2016 *)

Formula

a(n+3) = 6*a(n+2) - 5*a(n+1)+ 5*a(n) with n>=0, a(0) = 1, a(1) = 5, a(2) = 26.
G.f.: (-1 + x - x^2)/(-1 + 6*x - 5*x^2 + 5*x^3). - R. J. Mathar, Nov 07 2015

A255821 Numbers of words on {0,1,...,36} having no isolated zeros.

Original entry on oeis.org

1, 36, 1297, 46729, 1683577, 60656797, 2185374961, 78735837637, 2836736138665, 102203420474269, 3682238546710945, 132665625592223221, 4779746882367738841, 172207232713967895181, 6204372685172893559377, 223534399861459456068709
Offset: 0

Views

Author

Milan Janjic, Mar 07 2015

Keywords

Comments

The number p_n = a(n)/37^n equals the probability that in n trials in single zero (European) Roulette zero will not appear isolated. For example, p_10 is approximately 0.021.

Crossrefs

Programs

  • Mathematica
    RecurrenceTable[{a[0] == 1, a[1] == 36,  a[2]== 1297, a[n] == 37 a[n - 1] - 36 a[n - 2] + 36 a[n - 3]}, a[n], {n, 0, 15}]
    LinearRecurrence[{37,-36,36}, {1, 36, 1297}, 100] (* G. C. Greubel, Jun 02 2016 *)
  • PARI
    Vec(-(x^2-x+1)/(36*x^3-36*x^2+37*x-1) + O(x^100)) \\ Colin Barker, Mar 09 2015

Formula

G.f.: -(x^2 - x + 1)/(36*x^3 - 36*x^2 + 37*x - 1). - Colin Barker, Mar 09 2015
a(n) = 37*a(n-1) - 36*a(n-2) + 36*a(n-3). - G. C. Greubel, Jun 02 2016
Showing 1-4 of 4 results.