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 1-10 of 10 results.

A171692 Triangle read by rows: absolute values of odd-numbered rows of A159041.

Original entry on oeis.org

1, 1, 10, 1, 1, 56, 246, 56, 1, 1, 246, 4047, 11572, 4047, 246, 1, 1, 1012, 46828, 408364, 901990, 408364, 46828, 1012, 1, 1, 4082, 474189, 9713496, 56604978, 105907308, 56604978, 9713496, 474189, 4082, 1, 1, 16368, 4520946, 193889840, 2377852335, 10465410528, 17505765564, 10465410528, 2377852335, 193889840, 4520946, 16368, 1
Offset: 0

Views

Author

Roger L. Bagula, Dec 15 2009

Keywords

Examples

			Irregular triangle begins as:
  1;
  1,   10,     1;
  1,   56,   246,     56,      1;
  1,  246,  4047,  11572,   4047,    246,     1;
  1, 1012, 46828, 408364, 901990, 408364, 46828, 1012, 1;
		

Crossrefs

Programs

  • Mathematica
    (* First program *)
    f[x_, y_, m_]:= 2^(m+1)*Exp[2^m*x]/((1 -y*Exp[x])*(1 +(2^(m+1) -1)*Exp[2^m*x]));
    Table[CoefficientList[SeriesCoefficient[Series[((1-y)^(n+1)/(2*y))*n!*f[x, y, 0], {x,0,30}], n], y], {n, 2, 20, 2}]//Flatten (* modified by G. C. Greubel, Mar 18 2022 *)
    (* Second program *)
    A008292[n_, k_]:= Sum[(-1)^j*(k-j)^n*Binomial[n+1, j], {j,0,k}];
    T[n_, k_]:= T[n, k]= If[k==0 || k==n, 1, If[k<=Floor[n/2], T[n, k-1] + (-1)^k*A008292[n+2, k+1], T[n, n-k] ]]; (* T = A159041 *)
    A171692[n_, k_]:= Abs[T[2*n, k]];
    Table[A171692[n, k], {n,0,12}, {k,0,2*n}]//Flatten (* G. C. Greubel, Mar 18 2022 *)
  • Sage
    def A008292(n,k): return sum( (-1)^j*(k-j)^n*binomial(n+1,j) for j in (0..k) )
    @CachedFunction
    def A159041(n,k):
        if (k==0 or k==n): return 1
        elif (k <= (n//2)): return A159041(n,k-1) + (-1)^k*A008292(n+2,k+1)
        else: return A159041(n,n-k)
    def A171692(n,k): return abs( A159041(2*n, k) )
    flatten([[A171692(n,k) for k in (0..2*n)] for n in (0..12)]) # G. C. Greubel, Mar 18 2022

Formula

T(n, k) = coefficients of (g(x, y)), where g(x, y) = n! * ((1-y)^(n+1)/(2*y)) * f(x, y, 0), with f(x, y, m) = 2^(m+1)*exp(2^m*x)/((1 -y*exp(x))*(1 +(2^(m+1) -1)*exp(2^m*x))).
From G. C. Greubel, Mar 18 2022: (Start)
T(n, k) = abs( A159041(2*n, k) ).
T(n, n-k) = T(n, k). (End)

Extensions

Edited by N. J. A. Sloane, May 10 2013
More terms from Jean-François Alcover, Feb 14 2014
Edited by G. C. Greubel, Mar 18 2022

A225434 Apply the triangle-to-triangle transformation described in the Comments in A159041 to the triangle in A142459.

Original entry on oeis.org

1, 1, 1, 1, -58, 1, 1, -307, -307, 1, 1, -1556, 12006, -1556, 1, 1, -7805, 140722, 140722, -7805, 1, 1, -39054, 1461615, -5647300, 1461615, -39054, 1, 1, -195303, 14287093, -109642851, -109642851, 14287093, -195303, 1, 1, -976552, 135028828, -1838120344, 4873361350, -1838120344, 135028828, -976552, 1
Offset: 0

Views

Author

Roger L. Bagula, May 07 2013

Keywords

Examples

			The triangle begins:
  1;
  1,       1;
  1,     -58,        1;
  1,    -307,     -307,          1;
  1,   -1556,    12006,      -1556,          1;
  1,   -7805,   140722,     140722,      -7805,        1;
  1,  -39054,  1461615,   -5647300,    1461615,   -39054,       1;
  1, -195303, 14287093, -109642851, -109642851, 14287093, -195303, 1;
		

Crossrefs

Programs

  • Maple
    See A159041.
  • Mathematica
    (* First program *)
    t[n_, k_, m_]:= t[n, k, m]= If[k==0 || k==n, 1, (m*(n+1)-m*(k+1)+1)*t[n-1,k-1,m] + (m*(k+1)-(m-1))*t[n-1,k,m] ]; (* t(n,k,4)=A142459 *)
    p[x_, n_]:= p[x, n]= Sum[x^i*If[i==Floor[n/2] && Mod[n, 2]==0, 0, If[i<=Floor[n/2], (-1)^i*t[n,i,4], (-1)^(n-i+1)*t[n,i,4]]], {i,0,n}]/(1-x);
    Flatten[Table[CoefficientList[p[x, n], x], {n,0,12}]]
    (* Second program *)
    t[n_, k_, m_]:= t[n, k, m]= If[k==1 || k==n, 1, (m*(n+1)-m*(k+1)+1)*t[n-1,k-1,m] + (m*(k+1)-(m-1))*t[n-1,k,m]];
    T[n_, k_]:= T[n, k]= If[k==0 || k==n, 1, If[k<=Floor[n/2], T[n, k-1] + (-1)^k*t[n+2,k+1,4], T[n, n-k]]];
    Table[T[n, k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Mar 19 2022 *)
  • Sage
    @CachedFunction
    def T(n, k, m):
        if (k==1 or k==n): return 1
        else: return (m*(n-k)+1)*T(n-1, k-1, m) + (m*k-m+1)*T(n-1, k, m)
    def A142459(n,k): return T(n,k,4)
    @CachedFunction
    def A225434(n,k):
        if (k==0 or k==n): return 1
        elif (k <= (n//2)): return A225434(n,k-1) + (-1)^k*A142459(n+2,k+1)
        else: return A225434(n,n-k)
    flatten([[A225434(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 19 2022

Formula

A triangle of polynomial coefficients: p(x,n) = Sum_{i=0..n} ( x^i * if(i = floor(n/2) and (n mod 2) = 0, 0, if(i <= floor(n/2), (-1)^i*A142459(n+1, i+1), (-1)^(n-i+1)*A142459(n+1, i+1) ) )/(1-x).
T(n, k) = T(n,k-1) + (-1)^k*A142459(n+2,k+1) if k <= floor(n/2), otherwise T(n, n-k), with T(n, 0) = T(n, n) = 1. - G. C. Greubel, Mar 19 2022

Extensions

Edited by N. J. A. Sloane, May 11 2013

A225483 Triangle T(n, k) = Sum_{j=0..k} (-1)^(k-j)*A159041(2*n+1, j), read by rows.

Original entry on oeis.org

1, 1, -26, 1, 1, -120, 1192, -120, 1, 1, -502, 14609, -88736, 14609, -502, 1, 1, -2036, 152638, -2205524, 9890752, -2205524, 152638, -2036, 1, 1, -8178, 1479727, -45541628, 424761262, -1551163136, 424761262, -45541628, 1479727, -8178, 1
Offset: 0

Views

Author

Roger L. Bagula, May 08 2013

Keywords

Examples

			The triangle begins:
  1;
  1,   -26,      1;
  1,  -120,   1192,     -120,       1;
  1,  -502,  14609,   -88736,   14609,     -502,      1;
  1, -2036, 152638, -2205524, 9890752, -2205524, 152638, -2036, 1;
		

Crossrefs

Programs

  • Mathematica
    (* First program *)
    Needs["Combinatorica`"];
    p[n_, x_]:= p[n,x]= Sum[If[i==Floor[n/2] && Mod[n, 2]==0, 0, If[i<=Floor[n/2], (-1)^i*Eulerian[n+1, i]*x^i, (-1)^(n-i+1)*Eulerian[n+1, i]*x^i]], {i,0,n}]/(1- x^2);
    Table[CoefficientList[p[x, 2*n], x], {n,0,10}]//Flatten
    (* Second program *)
    A008292[n_, k_]:= A008292[n, k]= Sum[(-1)^j*(k-j)^n*Binomial[n+1,j], {j,0,k}];
    f[n_, k_]:= f[n, k]= If[k==0 || k==n, 1, If[k<=Floor[n/2], f[n, k-1] + (-1)^k*A008292[n+2, k+1], f[n, n-k]]]; (* f = A159041 *)
    T[n_, k_]:= T[n, k]= Sum[(-1)^(k-j)*f[2*n+1,j], {j,0,k}];
    Table[T[n, k], {n,0,10}, {k,0,2*n}]//Flatten (* G. C. Greubel, Mar 29 2022 *)
  • Sage
    def A008292(n, k): return sum( (-1)^j*(k-j)^n*binomial(n+1, j) for j in (0..k) )
    @CachedFunction
    def f(n, k): # A159041
        if (k==0 or k==n): return 1
        elif (k <= (n//2)): return f(n, k-1) + (-1)^k*A008292(n+2, k+1)
        else: return f(n, n-k)
    def A225483(n,k): return sum( (-1)^(k-j)*f(2*n+1,j) for j in (0..k) )
    flatten([[A225483(n, k) for k in (0..2*n)] for n in (0..12)]) # G. C. Greubel, Mar 29 2022

Formula

T(n, k) = [x^k]( A159041(x,n)/(x+1) ).
From G. C. Greubel, Mar 29 2022: (Start)
T(n, k) = Sum_{j=0..k} (-1)^(k-j)*A159041(2*n+1, j).
T(n, 2*n-k) = T(n, k). (End)

Extensions

Edited by G. C. Greubel, Mar 29 2022

A225356 Triangle T(n, k) = T(n, k-1) + (-1)^k*A060187(n+2,k+1) if k <= floor(n/2), otherwise T(n, n-k), with T(n, 0) = T(n, n) = 1, read by rows.

Original entry on oeis.org

1, 1, 1, 1, -22, 1, 1, -75, -75, 1, 1, -236, 1446, -236, 1, 1, -721, 9822, 9822, -721, 1, 1, -2178, 58479, -201244, 58479, -2178, 1, 1, -6551, 325061, -2160227, -2160227, 325061, -6551, 1, 1, -19672, 1736668, -19971304, 49441990, -19971304, 1736668, -19672, 1
Offset: 0

Views

Author

Roger L. Bagula, May 07 2013

Keywords

Examples

			The triangle begins:
  1;
  1,      1;
  1,    -22,       1;
  1,    -75,     -75,         1;
  1,   -236,    1446,      -236,        1;
  1,   -721,    9822,      9822,     -721,         1;
  1,  -2178,   58479,   -201244,    58479,     -2178,       1;
  1,  -6551,  325061,  -2160227, -2160227,    325061,   -6551,      1;
  1, -19672, 1736668, -19971304, 49441990, -19971304, 1736668, -19672, 1;
		

Crossrefs

Programs

  • Mathematica
    (* First program *)
    q[x_, n_]= (1-x)^(n+1)*Sum[(2*m+1)^n*x^m, {m, 0, Infinity}];
    t[n_, m_]:= t[n, m]= Table[CoefficientList[q[x, k], x], {k,0,15}][[n+1, m+1]];
    p[x_, n_]:= p[x, n]= Sum[x^i*If[i==Floor[n/2] && Mod[n, 2]==0, 0, If[i <= Floor[n/2], (-1)^i*t[n, i], (-1)^(n-i+1)*t[n, i]]], {i,0,n}]/(1-x);
    Flatten[Table[CoefficientList[p[x, n], x], {n,10}]]
    (* Second Program *)
    A060187[n_, k_]:= Sum[(-1)^(k-i)*Binomial[n, k-i]*(2*i-1)^(n-1), {i,k}];
    T[n_, k_]:= T[n, k]= If[k==0 || k==n, 1, If[k<=Floor[n/2], T[n, k-1] +(-1)^k*A060187[n+2, k+1], T[n, n-k] ]];
    Table[T[n, k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Mar 18 2022 *)
  • Sage
    def A060187(n,k): return sum( (-1)^(k-j)*(2*j-1)^(n-1)*binomial(n, k-j) for j in (1..k) )
    @CachedFunction
    def A225356(n,k):
        if (k==0 or k==n): return 1
        elif (k <= (n//2)): return A225356(n,k-1) + (-1)^k*A060187(n+2,k+1)
        else: return A225356(n,n-k)
    flatten([[A225356(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 18 2022

Formula

T(n, k) = T(n, k-1) + (-1)^k*A060187(n+2,k+1) if k <= floor(n/2), otherwise T(n, n-k), with T(n, 0) = T(n, n) = 1.

Extensions

Edited by N. J. A. Sloane, May 11 2013
Edited by G. C. Greubel, Mar 18 2022

A171693 Expansion of g.f.: 2^(1+floor(n/2))*n!*((1-y)^(n+1)/(1+y))*f(x, y, m), where f(x, y, m) = 2^(m+1)*exp(2^m*t)/((1-y*exp(t))*(1 + (2^(m+1)-1)*exp(2^m*t))), and m = 0.

Original entry on oeis.org

1, -1, 14, -1, 4, -16, 504, -16, 4, -34, 372, 2178, 35288, 2178, 372, -34, 496, -5888, 65728, 749824, 4185760, 749824, 65728, -5888, 496, -11056, 154912, -767856, 23350656, 230640288, 770603712, 230640288, 23350656, -767856, 154912, -11056
Offset: 0

Views

Author

Roger L. Bagula, Dec 15 2009

Keywords

Examples

			Irregular triangle begins as:
    1;
   -1,    14,    -1;
    4,   -16,   504,    -16,       4;
  -34,   372,  2178,  35288,    2178,    372,   -34;
  496, -5888, 65728, 749824, 4185760, 749824, 65728, -5888, 496;
		

Crossrefs

Programs

  • Mathematica
    m= 0;
    f[t_, y_, m_]= 2^(m+1)*Exp[2^m*t]/((1-y*Exp[t])*(1+(2^(m+1)-1)*Exp[2^m*t]));
    T[n_]:= T[n]= CoefficientList[2^(1+Floor[n/2])*n!*(1-y)^(n+1)/(1 + y)*SeriesCoefficient[Series[f[t, y, m], {t,0,20}], n], y];
    Table[T[2*n+1], {n,0,12}]//Flatten (* modified by G. C. Greubel, Mar 30 2022 *)

Formula

G.f.: 2^(1+floor(n/2))*n!*((1-y)^(n+1)/(1+y))*f(x, y, m), where f(x, y, m) = 2^(m+1)*exp(2^m*t)/((1-y*exp(t))*(1 + (2^(m+1)-1)*exp(2^m*t))), and m = 0.

Extensions

Edited by G. C. Greubel, Mar 31 2022

A171694 Expansion of g.f.: 4^n*n!*(1-y)^(n+1)*f(x, y, m), where f(x, y, m) = 2^(m+1)*exp(2^m*t)/((1-y*exp(t))*(1 + (2^(m+1)-1)*exp(2^m*t))), and m = -2.

Original entry on oeis.org

1, 2, 2, 6, 20, 6, 26, 154, 190, 14, 150, 1160, 3428, 1352, 54, 1082, 9174, 50404, 51724, 10434, 62, 9366, 78476, 683962, 1376232, 734122, 65996, 966, 94586, 735410, 9096210, 30488714, 32703374, 8931318, 530534, -4786, 1091670, 7562000, 122859048, 611454960, 1132022084, 653476464, 111158184, 2715536, 71574
Offset: 0

Views

Author

Roger L. Bagula, Dec 15 2009

Keywords

Examples

			Triangle begins as:
      1;
      2,      2;
      6,     20,       6;
     26,    154,     190,       14;
    150,   1160,    3428,     1352,       54;
   1082,   9174,   50404,    51724,    10434,      62;
   9366,  78476,  683962,  1376232,   734122,   65996,    966;
  94586, 735410, 9096210, 30488714, 32703374, 8931318, 530534, -4786;
		

Crossrefs

Programs

  • Mathematica
    m= -2;
    f[t_, y_, m_]= 2^(m+1)*Exp[2^m*t]/((1-y*Exp[t])*(1+(2^(m+1)-1)*Exp[2^m*t]));
    Table[CoefficientList[4^n*n!*(1-y)^(n+1)*SeriesCoefficient[Series[f[t,y,m], {t,0,20}], n], y], {n,0,12}]//Flatten (* modified by G. C. Greubel, Mar 29 2022 *)

Formula

G.f.: 4^n*n!*(1-y)^(n+1)*f(x, y, m), where f(x, y, m) = 2^(m+1)*exp(2^m*t)/((1-y*exp(t))*(1 + (2^(m+1)-1)*exp(2^m*t))), and m = -2.

Extensions

Edited by G. C. Greubel, Mar 29 2022

A225433 Triangle T(n, k) = T(n, k-1) + (-1)^k*A142458(n+2, k+1) if k <= floor(n/2), otherwise T(n, n-k), with T(n, 0) = T(n, n) = 1, read by rows.

Original entry on oeis.org

1, 1, 1, 1, -38, 1, 1, -165, -165, 1, 1, -676, 4806, -676, 1, 1, -2723, 44452, 44452, -2723, 1, 1, -10914, 362895, -1346780, 362895, -10914, 1, 1, -43681, 2780367, -20297327, -20297327, 2780367, -43681, 1, 1, -174752, 20554588, -263879264, 683233990, -263879264, 20554588, -174752, 1
Offset: 0

Views

Author

Roger L. Bagula, May 07 2013

Keywords

Examples

			The triangle begins:
  1;
  1,      1;
  1,    -38,       1;
  1,   -165,    -165,         1;
  1,   -676,    4806,      -676,         1;
  1,  -2723,   44452,     44452,     -2723,       1;
  1, -10914,  362895,  -1346780,    362895,  -10914,      1;
  1, -43681, 2780367, -20297327, -20297327, 2780367, -43681, 1;
		

Crossrefs

Programs

  • Maple
    See Maple program in A159041.
  • Mathematica
    (* First program *)
    T[n_, k_, m_]:= T[n, k, m]= If[k==0 || k==n, 1, (m*(n+1) -m*(k+1) +1)*T[n-1, k- 1, m] + (m*(k+1) -(m-1))*T[n-1, k, m] ];
    p[x_, n_]:= p[x, n]= Sum[x^i*If[i==Floor[n/2] && Mod[n, 2]==0, 0, If[i<= Floor[n/2], (-1)^i*T[n,i,3], -(-1)^(n-i)*T[n,i,3]]], {i,0,n}]/(1-x);
    Flatten[Table[CoefficientList[p[x, n], x], {n,0,12}]]
    (* Second program *)
    T[n_, k_, m_]:= T[n, k, m]= If[k==1 || k==n, 1, (m*n-m*k+1)*T[n-1, k-1, m] + (m*k-m+1)*T[n-1, k, m]];
    A142458[n_, k_]:= T[n,k,3];
    A225433[n_, k_]:= A225433[n, k]= If[k==0 || k==n, 1, If[k<=Floor[n/2], A225433[n, k-1] +(-1)^k*A142458[n+2, k+1], A225433[n, n-k]]];
    Table[A225433[n, k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Mar 19 2022 *)
  • Sage
    @CachedFunction
    def T(n, k, m):
        if (k==1 or k==n): return 1
        else: return (m*(n-k)+1)*T(n-1, k-1, m) + (m*k-m+1)*T(n-1, k, m)
    def A142458(n,k): return T(n,k,3)
    @CachedFunction
    def A225433(n,k):
        if (k==0 or k==n): return 1
        elif (k <= (n//2)): return A225433(n,k-1) + (-1)^k*A142458(n+2,k+1)
        else: return A225433(n,n-k)
    flatten([[A225433(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 19 2022

Formula

From G. C. Greubel, Mar 19 2022: (Start)
T(n, k) = T(n, k-1) + (-1)^k*A142458(n+2, k+1) if k <= floor(n/2), otherwise T(n, n-k), with T(n, 0) = T(n, n) = 1.
T(n, n-k) = T(n, k). (End)

Extensions

Edited by N. J. A. Sloane, May 11 2013
Edited by G. C. Greubel, Mar 19 2022

A171695 Expansion of g.f.: 2^(floor((n+1)/2))*n!*(1-y)^(n+1)*f(x, y, m), where f(x, y, m) = 2^(m+1)*exp(2^m*t)/((1-y*exp(t))*(1 + (2^(m+1)-1)*exp(2^m*t))), and m = 1.

Original entry on oeis.org

1, 1, 1, -1, 6, -1, -1, 7, 25, -7, 10, -44, 152, -20, -2, -26, 198, -292, 1628, -642, 94, -154, 1000, -1954, 6416, 1586, -1400, 266, 1646, -13606, 51774, -75094, 175226, -73890, 15962, -1378, 1000, -3936, -4448, 190432, 37104, 779104, -472160, 133152, -15128
Offset: 0

Views

Author

Roger L. Bagula, Dec 15 2009

Keywords

Examples

			Triangle begins as:
     1;
     1,      1;
    -1,      6,    -1;
    -1,      7,    25,     -7;
    10,    -44,   152,    -20,     -2;
   -26,    198,  -292,   1628,   -642,     94;
  -154,   1000, -1954,   6416,   1586,  -1400,     266;
  1646, -13606, 51774, -75094, 175226, -73890,   15962,  -1378;
  1000,  -3936, -4448, 190432,  37104, 779104, -472160, 133152, -15128;
		

Crossrefs

Programs

  • Mathematica
    m= 1;
    f[t_, y_, m_]= 2^(m+1)*Exp[2^m*t]/((1-y*Exp[t])*(1+(2^(m+1)-1)*Exp[2^m*t]));
    Table[CoefficientList[2^(Floor[(n+1)/2])*n!*(1-y)^(n+1)*SeriesCoefficient[ Series[f[t,y,m], {t,0,20}], n], y], {n,0,12}]//Flatten (* modified by G. C. Greubel, Mar 29 2022 *)

Formula

G.f.: 2^(floor((n+1)/2))*n!*(1-y)^(n+1)*f(x, y, m), where f(x, y, m) = 2^(m+1)*exp(2^m*t)/((1-y*exp(t))*(1 + (2^(m+1)-1)*exp(2^m*t))), and m = 1.

Extensions

Edited by G. C. Greubel, Mar 29 2022

A225532 Triangle T(n, k) = abs(A225483(n/2, k)) if (n mod 2 = 0), otherwise abs(A225482((n-1)/2, k) - A225483((n-1)/2, k-1)), read by rows.

Original entry on oeis.org

1, 1, 1, 1, 26, 1, 1, 27, 27, 1, 1, 120, 1192, 120, 1, 1, 121, 1312, 1312, 121, 1, 1, 502, 14609, 88736, 14609, 502, 1, 1, 503, 15111, 103345, 103345, 15111, 503, 1, 1, 2036, 152638, 2205524, 9890752, 2205524, 152638, 2036, 1, 1, 2037, 154674, 2358162, 12096276, 12096276, 2358162, 154674, 2037, 1
Offset: 0

Views

Author

Roger L. Bagula, May 09 2013

Keywords

Examples

			Triangle begins:
  1;
  1,   1;
  1,  26,     1;
  1,  27,    27,      1;
  1, 120,  1192,    120,      1;
  1, 121,  1312,   1312,    121,     1;
  1, 502, 14609,  88736,  14609,   502,   1;
  1, 503, 15111, 103345, 103345, 15111, 503, 1;
		

Crossrefs

Programs

  • Mathematica
    (* First program *)
    Needs["Combinatorica`"];
    p[n_, x_]:= p[n,x]= Sum[If[i==Floor[n/2] && Mod[n, 2]==0, 0, If[i<=Floor[n/2], (-1)^i*Eulerian[n+1,i]*x^i, (-1)^(n-i+1)*Eulerian[n+1,i]*x^i]], {i,0,n}]/(1 - x^2);
    q[n_, x_]= If[Mod[n,2]==0, (1-x)*p[n/2,x], p[(n+1)/2,x]];
    Table[Abs[CoefficientList[q[(4*n +(-1)^n +5)/2, x], x]], {n,0,12}]//Flatten (* modified by G. C. Greubel, Mar 29 2022 *)
    (* Second program *)
    A008292[n_, k_]:= A008292[n, k]= Sum[(-1)^j*(k-j)^n*Binomial[n+1,j], {j,0,k}];
    f[n_, k_]:= f[n, k]= If[k==0 || k==n, 1, If[k<=Floor[n/2], f[n,k-1] + (-1)^k*A008292[n+2,k+1], f[n,n-k]]]; (* f=A159041 *)
    A225483[n_, k_]:= Sum[(-1)^(k-j)*f[2*n+1,j], {j,0,k}];
    T[n_, k_]:= If[Mod[n,2]==0, A225483[n/2, k], A225483[(n-1)/2, k] - A225483[(n - 1)/2, k-1] ]//Abs;
    Table[T[n, k], {n,0,10}, {k,0,n}]//Flatten (* G. C. Greubel, Mar 29 2022 *)
  • Sage
    def A008292(n, k): return sum( (-1)^j*(k-j)^n*binomial(n+1, j) for j in (0..k) )
    @CachedFunction
    def f(n, k): # A159041
        if (k==0 or k==n): return 1
        elif (k <= (n//2)): return f(n, k-1) + (-1)^k*A008292(n+2, k+1)
        else: return f(n, n-k)
    def A225483(n,k): return sum( (-1)^(k-j)*f(2*n+1,j) for j in (0..k) )
    @CachedFunction
    def A225532(n,k):
        if (n%2==0): return abs(A225483(n/2, k))
        else: return abs( A225483((n-1)/2, k) - A225483((n-1)/2, k-1) )
    flatten([[A225532(n, k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 29 2022

Formula

From G. C. Greubel, Mar 29 2022: (Start)
T(n, k) = abs(A225483(n/2, k)) if (n mod 2 = 0), otherwise abs(A225482((n-1)/2, k) - A225483((n-1)/2, k-1)).
T(n, n-k) = T(n, k). (End)

Extensions

Edited by G. C. Greubel, Mar 29 2022

A347816 Prime numbers p such that both 15 and 85 are quadratic nonresidue (mod p).

Original entry on oeis.org

13, 29, 31, 41, 47, 79, 83, 139, 157, 199, 211, 263, 269, 373, 379, 383, 401, 433, 439, 443, 449, 457, 467, 499, 521, 563, 571, 577, 587, 613, 619, 641, 647, 691, 733, 751, 757, 809, 811, 821, 863, 881, 929, 937, 941, 991, 1033, 1049, 1051, 1061
Offset: 1

Views

Author

Sela Fried, Sep 15 2021

Keywords

Comments

Primes p such that E_6(x)/(x + 1) is irreducible (mod p) where E_6(x) is the Eulerian polynomial and E_6(x)/(x + 1) = x^4 + 56x^3 + 246x^2 + 56x + 1. (See A159041.)
The sequence is infinite.
It is the intersection of A038888 and A038972.

Crossrefs

Programs

  • Maple
    alias(ls = NumberTheory:-LegendreSymbol):
    isA347816 := k -> isprime(k) and ls(15, k) = -1 and ls(85, k) = -1:
    A347816List := upto -> select(isA347816, [`$`(3..upto)]):
    A347816List(1061); # Peter Luschny, Sep 16 2021
  • Mathematica
    Select[Prime@Range[180], JacobiSymbol[15, #] == -1 && JacobiSymbol[85,#]==-1 &] (* Stefano Spezia, Sep 16 2021 *)
  • PARI
    isok(p) = isprime(p) && (kronecker(15,p)==-1) && (kronecker(85,p)==-1); \\ Michel Marcus, Sep 16 2021
    
  • Python
    from sympy.ntheory import legendre_symbol, primerange
    A347816_list = [p for p in primerange(3,10**5) if legendre_symbol(15,p) == legendre_symbol(85,p) == -1] # Chai Wah Wu, Sep 16 2021
Showing 1-10 of 10 results.