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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A134727 Successive digits of members of the Padovan sequence A000931(n).

Original entry on oeis.org

1, 0, 0, 1, 0, 1, 1, 1, 2, 2, 3, 4, 5, 7, 9, 1, 2, 1, 6, 2, 1, 2, 8, 3, 7, 4, 9, 6, 5, 8, 6, 1, 1, 4, 1, 5, 1, 2, 0, 0, 2, 6, 5, 3, 5, 1, 4, 6, 5, 6, 1, 6, 8, 1, 6, 1, 0, 8, 1, 1, 4, 3, 2, 1, 8, 9, 7, 2, 5, 1, 3, 3, 3, 2, 9, 4, 4, 1, 0, 5, 8, 4, 2, 7, 7, 3, 9, 1, 0, 2, 5, 2
Offset: 1

Views

Author

Omar E. Pol, Nov 10 2007

Keywords

Crossrefs

Cf. A000931.

Programs

  • Mathematica
    Flatten[IntegerDigits/@ LinearRecurrence[{0,1,1},{1,0,0},50]] (* Harvey P. Dale, Dec 31 2022 *)

A140514 a(n) = A000931(n+4) - A010060(n).

Original entry on oeis.org

0, 0, 0, 1, 1, 2, 3, 3, 4, 7, 9, 11, 16, 20, 27, 37, 48, 65, 86, 113, 151, 199, 264, 351, 465, 615, 815, 1081, 1431, 1897, 2513, 3328, 4409, 5842, 7739, 10251, 13581, 17990, 23832, 31572, 41824, 55404, 73395, 97229, 128800, 170625, 226030, 299425, 396655
Offset: 0

Views

Author

Roger L. Bagula and Gary W. Adamson, Jul 01 2008

Keywords

Crossrefs

Programs

  • Mathematica
    A000931 := LinearRecurrence[{0, 1, 1}, {1, 0, 0}, 500]; Table[A000931[[n + 5]] - ThueMorse[n], {n, 0, 100}] (* G. C. Greubel, Jan 14 2018 *)

Formula

a(n) = A000931(n+4) - A010060(n).

Extensions

Definition simplified, indices clarified, references converted to links, Nov 16 2010

A144401 Padovan ( A000931) version of A038137: expansion of polynomials as antidiagonal: p(x,n)=1/(1-x-x^3)^n.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 3, 3, 2, 1, 4, 6, 6, 3, 1, 5, 10, 13, 11, 4, 1, 6, 15, 24, 27, 18, 6, 1, 7, 21, 40, 55, 51, 30, 9, 1, 8, 28, 62, 100, 116, 94, 50, 13, 1, 9, 36, 91, 168, 231, 234, 171, 81, 19, 1, 10, 45, 128, 266, 420, 505, 460, 303, 130, 28, 1, 11, 55, 174, 402, 714, 987, 1065
Offset: 1

Views

Author

Roger L. Bagula and Gary W. Adamson, Oct 03 2008

Keywords

Comments

Row sums are: 1, 2, 4, 9, 20, 44, 97, 214, 472, 1041, 2296, 5064, 11169, 24634, 54332 (cf. A008998).
These polynomials are sort of pseudo-combinations with the last element Padovan instead of one.
If you subtract the binomial triangle sequence you get:
{0},
{0, 0},
{0, 0, 0},
{0, 0, 0, 1},
{0, 0, 0, 2, 2},
{0, 0, 0, 3, 6, 3},
{0, 0, 0, 4, 12, 12, 5},
{0, 0, 0, 5, 20, 30, 23, 8},
{0, 0, 0, 6, 30, 60, 66, 42, 12}

Examples

			{1},
{1, 1},
{1, 2, 1},
{1, 3, 3, 2},
{1, 4, 6, 6, 3},
{1, 5, 10, 13, 11, 4},
{1, 6, 15, 24, 27, 18, 6},
{1, 7, 21, 40, 55, 51, 30, 9},
{1, 8, 28, 62, 100, 116, 94, 50, 13},
{1, 9, 36, 91, 168, 231, 234, 171, 81, 19},
{1, 10, 45, 128, 266, 420, 505, 460, 303, 130, 28},
{1, 11, 55, 174, 402, 714, 987, 1065, 879, 527, 208, 41},
{1, 12, 66, 230, 585, 1152, 1792, 2220, 2175, 1640, 906, 330, 60},
{1, 13, 78, 297, 825, 1782, 3072, 4278, 4815, 4320, 3006, 1539, 520, 88},
{1, 14, 91, 376, 1133, 2662, 5028, 7752, 9807, 10122, 8391, 5424, 2586, 816, 129}
		

Crossrefs

Programs

  • Mathematica
    Clear[f, b, a, g, h, n, t]; f[t_, n_] = 1/(1 - t - t^3)^n; a = Table[Table[SeriesCoefficient[Series[f[t, m], {t, 0, 30}], n], {n, 0, 30}], {m, 1, 31}]; b = Table[Table[a[[n - m + 1]][[m]], {m, 1, n }], {n, 1, 15}]; Flatten[b]

Formula

p(x,n)=1/(1-x-x^3)^n; t(n,m)=anti_diagonal_expansion(p(x,n)).

A144413 a(n) = Sum_{k=0..n} (-1)^k * binomial(n, k) * A000931(n-k+4).

Original entry on oeis.org

0, 1, -1, 1, 0, -3, 10, -24, 49, -89, 145, -208, 245, -174, -176, 1121, -3185, 7137, -13920, 24301, -37926, 51256, -53615, 20407, 97265, -386224, 984549, -2083934, 3896480, -6537023, 9734175, -12231999, 10690624, 2126301, -39992150, 126414472, -297132815, 598577351, -1075051951, 1730868336, -2443923755
Offset: 0

Views

Author

Roger L. Bagula and Gary W. Adamson, Sep 30 2008

Keywords

Crossrefs

Programs

  • Magma
    I:=[0,1,1]; [n le 3 select I[n] else -3*Self(n-1) -2*Self(n-2) +Self(n-3): n in [1..51]]; // G. C. Greubel, Mar 27 2021
    
  • Mathematica
    (* First program *)
    b[n_]:= b[n]= If[n==0, 0, If[n<3, 1, b[n-2] +b[n-3]]];
    a[n_]:= Sum[(-1)^m*Binomial[n, m]*b[n-m], {m,0,n}];
    Table[a[n], {n, 0, 50}]
    (* Second program *)
    LinearRecurrence[{-3,-2,1}, {0,1,-1}, 51] (* G. C. Greubel, Mar 27 2021 *)
  • Sage
    @CachedFunction
    def A000931(n): return 1 if n==0 else sum( binomial(k, n-2*k-3) for k in (0..floor((n-3)/2)))
    def A144413(n): return sum( (-1)^k*binomial(n, k)*A000931(n-k+4) for k in (0..n))
    [A144413(n) for n in (0..50)] # G. C. Greubel, Mar 27 2021

Formula

From R. J. Mathar, Jan 21 2009: (Start)
a(n) = -3*a(n-1) - 2*a(n-2) + a(n-3).
G.f.: x*(1 +2*x)/(1 +3*x +2*x^2 -x^3). (End)

Extensions

Terms a(30) onward added and edited by G. C. Greubel, Mar 27 2021

A145462 Eigentriangle, row sums = the Padovan sequence, A000931.

Original entry on oeis.org

1, 1, 1, -1, 1, 2, 0, -1, 2, 2, 1, 0, -2, 2, 3, -1, 1, 0, -2, 3, 4, 0, -1, 2, 0, -3, 4, 5, 1, 0, -2, 2, 0, -4, 5, 7, -1, 1, 0, -2, 3, 0, -5, 7, 9, 0, -1, 2, 0, -3, 4, 0, -7, 9, 12, 1, 0, -2, 2, 0, -4, 5, 0, -9, 12, 16, -1, 1, 0, -2, 3, 0, -5, 7, 0, -12, 16, 21
Offset: 6

Views

Author

Gary W. Adamson, Oct 10 2008

Keywords

Comments

Right border = Padovan sequence starting with offset 6.
Row sums = Padovan sequence starting with offset 7.
Sum of n-th row terms = rightmost term of next row.

Examples

			First few rows of the triangle =
1;
1, 1;
-1, 1, 2;
0, -1, 2, 2;
1, 0, -2, 2, 3;
-1, 1, 0, -2, 3, 4;
0, -1, 2, 0, -3, 4, 5;
1, 0, -2, 2, 0, -4, 5, 7;
-1, 1, 0, -2, 3, 0, -5, 7, 9;
0, -1, 2, 0, -3, 4, 0, -7, 9, 12;
1, 0, -2, 2, 0, -4, 5, 0, -9, 12, 16;
...
Example: Row 10 = (1, 0, -2, 2, 3) with A000931(10) = 3, rightmost term. This row = the termwise products of (1, 0, -1, 1, 1) and (1, 1, 2, 2, 3); where the Padovan sequence starting with offset 6 = (1, 1, 2, 2, 3, 4, 5, 7, 9,...).
		

Crossrefs

Formula

Triangle read by rows, T(n,k) = M * (A000931 * 0^(n-k)). M = an infinite lower triangular matrix with A106510 in every column: (1, 1, -1, 0, 1, -1, 0, 1, -1,...); and A000931 is a diagonalized infinite lower triangular matrix with the Padovan sequence starting with offset 6: (1, 1, 2, 2, 3, 4, 5, 7, 9,...) as the main diagonal and the rest zeros.

A146973 Eigentriangle, row sums = A000931 starting with offset 3.

Original entry on oeis.org

1, -1, 1, 2, -1, 0, -2, 2, 0, 1, 3, -2, 0, -1, 1, -3, 3, 0, 2, -1, 1, 4, -3, 0, -2, 2, -1, 2, -4, 4, 0, 3, -2, 2, -2, 2, 5, -4, 0, -3, 3, -2, 4, -2, 3, -5, 5, 0, 4, -3, 3, -4, 4, -3, 4, 6, -5, 0, -4, 4, -3, 6, -4, 5, -6, 6, 0, 5, -4, 4, -6, 6, -6, 8, -5, 7
Offset: 3

Views

Author

Gary W. Adamson, Nov 03 2008

Keywords

Comments

Row sums and right border = the Padovan sequence, A000931 starting with offset 3: (1, 1, 0, 1, 1, 1, 2, 2, 3,...).
Sum of n-th row terms = rightmost term of next row.

Examples

			First few rows of the triangle =
  1;
  -1, 1;
  2, -1, 0;
  -2, 2, 0, 1;
  3, -2, 0, -1, 1;
  -3, 3, 0, 2, -1, 1;
  4, -3, 0, -2, 2, -1, 2;
  -4, 4, 0, 3, -2, 2, -2, 2;
  5, -4, 0, -3, 3, -2, 4, -2, 3;
  -5, 5, 0, 4, -3, 3, -4, 4, -3, 4;
  6, -5, 0, -4, 4, -3, 6, -4, 6, -4, 5;
  -6, 6, 0, 5, -4, 4, -6, 6, -6, 8, -5, 7;
  7, -6, 0, -5, 5, -4, 8, -6, 9, -8, 10, -7, 9
  -7, 7, 0, 6, -5, 5, -8, 8, -9, 12, -10, 14, -9, 12;
  ...
Row 6 = (-2, 2, 0, 1) = termwise products of (-2, 2, 0, 1) and (1, 1, 0, 1).
		

Crossrefs

Cf. A000931.

Formula

Triangle read by rows, T * Q, where T = an infinite lower triangular matrix with (1, -1, 2, -2, 3, -3,...) in every column and Q = an infinite lower triangular matrix with the Padovan sequence, A000931 as the main diagonal starting with offset 3: (1, 1, 0, 1, 1, 1, 2, 2, 3,...). The rest of triangle Q = all zeros. This triangle = T * Q.

A152870 Indices of primes in the Padovan sequence A000931.

Original entry on oeis.org

8, 9, 10, 12, 13, 19, 24, 35, 42, 89, 133, 474, 671, 1267, 1578, 2008, 2215, 2294, 4168, 5558, 6572, 8566, 11235, 18742, 35839, 44264, 536490, 727739
Offset: 1

Views

Author

Roger L. Bagula, Dec 14 2008

Keywords

Crossrefs

Programs

  • Mathematica
    a[0] = 1; a[1] = 0; a[2] = 0;
    a[n_] := a[n] = a[n - 2] + a[n - 3];
    Flatten[Table[If[PrimeQ[a[n]], n, {}], {n, 0, 10000}]]
  • PARI
    v=[1,1,1];for(n=8,1e4,v=[v[2],v[3],v[1]+v[2]];if(ispseudoprime(v[3]),print1(n", "))) \\ Charles R Greathouse IV, Nov 07 2011

Formula

a(n) = A112882(n) + 5. - Amiram Eldar, Nov 10 2024

Extensions

a(23)-a(26) from Charles R Greathouse IV, Nov 07 2011
a(27)-a(28) calculated from the data at A112882 by Amiram Eldar, Nov 10 2024

A167385 a(n)= sum_{i=7..n+6} A000931(i).

Original entry on oeis.org

1, 3, 5, 8, 12, 17, 24, 33, 45, 61, 82, 110, 147, 196, 261, 347, 461, 612, 812, 1077, 1428, 1893, 2509, 3325, 4406, 5838, 7735, 10248, 13577, 17987, 23829, 31568, 41820, 55401, 73392, 97225, 128797, 170621, 226026, 299422, 396651, 525452, 696077, 922107, 1221533
Offset: 0

Views

Author

Roger L. Bagula, Nov 02 2009

Keywords

Crossrefs

Cf. A018917.

Programs

  • Mathematica
    Clear[f, g, n]
    f[0] = 0; f[1] = 1; f[2] = 1; f[n_] := f[n] = f[n - 2] + f[n - 3];
    g[n_] := Sum[f[i + 3], {i, 0, n}]
    Table[g[n], {n, 0, 30}]

Formula

a(n+1)/a(n)-> A060005 as n->infinity.
G.f.: (1+x)^2/((x-1)*(x^3+x^2-1)). a(n)= +a(n-1) +a(n-2) -a(n-4). [Nov 05 2009]
a(n) = A000931(n+12)-4. [Nov 05 2009]

Extensions

Notation normalized, definition corrected, g.f. added - The Assoc. Editors of the OEIS, Nov 05 2009

A173692 a(n) = ceiling(A000931(n)/2).

Original entry on oeis.org

0, 1, 1, 1, 1, 1, 2, 2, 3, 4, 5, 6, 8, 11, 14, 19, 25, 33, 43, 57, 76, 100, 133, 176, 233, 308, 408, 541, 716, 949, 1257, 1665, 2205, 2921, 3870, 5126, 6791, 8996, 11917, 15786, 20912, 27703, 36698, 48615, 64401, 85313, 113015, 149713, 198328, 262728, 348041, 461056
Offset: 0

Views

Author

Roger L. Bagula, Nov 25 2010

Keywords

Crossrefs

Cf. A000931.

Programs

  • Mathematica
    a[0] = 0; a[1] = 1; a[2] = 1;
    a[n_] := a[n] = a[n - 2] + a[n - 3]
    Table[a[n] - Floor[a[n]/2], {n, 0, 30}]
  • PARI
    concat(0, Vec(x*(1 + x)*(1 - x^3 - x^7) / ((1 - x)*(1 - x^2 - x^3)*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)) + O(x^40))) \\ Colin Barker, Feb 26 2020

Formula

a(n) = A000931(n) - floor(A000931(n)/2).
a(n) = a(n-2) + a(n-3) + a(n-7) - a(n-9) - a(n-10). - R. J. Mathar, Mar 11 2012
G.f.: x*(1 + x)*(1 - x^3 - x^7) / ((1 - x)*(1 - x^2 - x^3)*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)). - Colin Barker, Feb 26 2020

Extensions

More terms from Jinyuan Wang, Feb 26 2020

A176505 Triangle T(n,m) read by rows: T(n,m) = a(n) - a(m) - a(n-m) + 1, where a(n) = A000931(n+4).

Original entry on oeis.org

1, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 2, 3, 2, 3, 2, 1, 1, 1, 2, 3, 4, 4, 4, 4, 3, 2, 1, 1, 2, 4, 5, 5, 6, 5, 5, 4, 2, 1
Offset: 0

Views

Author

Roger L. Bagula, Apr 19 2010

Keywords

Examples

			Triangle:
{1},
{1, 1},
{1, 0, 1},
{1, 0, 0, 1},
{1, 1, 1, 1, 1},
{1, 0, 1, 1, 0, 1},
{1, 1, 1, 2, 1, 1, 1},
{1, 1, 2, 2, 2, 2, 1, 1},
{1, 1, 2, 3, 2, 3, 2, 1, 1},
{1, 2, 3, 4, 4, 4, 4, 3, 2, 1},
{1, 2, 4, 5, 5, 6, 5, 5, 4, 2, 1},
...
T(6,3) = a(6) - a(3) - a(6-3) + 1 = a(6) - 2 * a(3) + 1 = 3 - (2 * 1) + 1 = 2. - _Indranil Ghosh_, Feb 17 2017
		

Crossrefs

Cf. A000931.

Programs

  • Mathematica
    a[0] := 0; a[1] := 1; a[2] := 1;
    a[n_] := a[n] = a[n - 2] + a[n - 3];
    t[n_, m_] := t[n, m] = a[n] - a[m] - a[n - m] + 1;
    Table[Table[t[n, m], {m, 0, n}], {n, 0, 10}];
    Flatten[%]

Formula

T(n,m) = a(n) - a(m) - a(n-m) + 1, a(n) = A000931(n+4).

Extensions

Name and formula sections corrected by Indranil Ghosh, Feb 17 2017
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