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.

A100615 Let N(n)(x) be the Nørlund polynomials as defined in A001898, with N(n)(1) equal to the usual Bernoulli numbers A027641/A027642. Sequence gives numerators of N(n)(2).

Original entry on oeis.org

1, -1, 5, -1, 1, 1, -5, -1, 7, 3, -15, -5, 7601, 691, -91, -35, 3617, 3617, -745739, -43867, 3317609, 1222277, -5981591, -854513, 5436374093, 1181820455, -213827575, -76977927, 213745149261, 23749461029, -249859397004145, -8615841276005, 238988952277727, 84802531453387
Offset: 0

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Author

N. J. A. Sloane, Dec 03 2004

Keywords

Comments

With the signs of A359738, the rational sequence reflects the identity B(z)^2 = (z + 1)*B(z) - z*B'(z), that goes back to Euler, where B(z) = z/(1 - e^(-z)) is the e.g.f. of the Bernoulli numbers with B(1) = 1/2. - Peter Luschny, Jan 23 2023

Examples

			1, -1, 5/6, -1/2, 1/10, 1/6, -5/42, -1/6, 7/30, 3/10, -15/22, -5/6, 7601/2730, 691/210, -91/6, -35/2, 3617/34, 3617/30, -745739/798, -43867/42, ... = A100615/A100616.
		

References

  • F. N. David, Probability Theory for Statistical Methods, Cambridge, 1949; see pp. 103-104. [There is an error in the recurrence for B_s^{(r)}.]

Crossrefs

Programs

  • Maple
    S:= series((x/(exp(x)-1))^2, x, 41):
    seq(numer(coeff(S,x,j)*j!), j=0..40); # Robert Israel, Jun 02 2015
    # Second program:
    a := n -> if n = 0 then 1 else numer(-n*bernoulli(n-1) - (n-1)*bernoulli(n)) fi:
    seq(a(n), n = 0..33);  # Peter Luschny, May 18 2023
  • Mathematica
    Table[Numerator@NorlundB[n, 2], {n, 0, 32}] (* Arkadiusz Wesolowski, Oct 22 2012 *)
    Table[If[n == 0, 1, -Numerator[n*BernoulliB[n - 1] + (n - 1)*BernoulliB[n]]], {n, 0,  33}] (* Peter Luschny, May 18 2023 *)
  • Maxima
    a(n):=sum((-1)^k*k!/(k+1)*sum(binomial(n,j)*stirling2(n-j,k)*bern(j),j,0,n-k),k,0,n); /* Vladimir Kruchinin, Jun 02 2015 */
    
  • PARI
    a(n) = numerator(sum(j=0, n, binomial(n,j)*bernfrac(n-j)*bernfrac(j))); \\ Michel Marcus, Mar 03 2020

Formula

E.g.f.: (x/(exp(x)-1))^2. - Vladeta Jovovic, Feb 27 2006
a(n) = numerator(Sum_{k=0..n}(-1)^k*k!/(k+1)*Sum_{j=0..n-k} C(n,j)*Stirling2(n-j,k)*B(j)), where B(n) is Bernoulli numbers. - Vladimir Kruchinin, Jun 02 2015
a(n) = numerator(Sum_{j=0..n} binomial(n,j)*Bernoulli(n-j)*Bernoulli(j)). - Fabián Pereyra, Mar 02 2020
a(n) = -numerator(n*B(n-1) + (n-1)*B(n)) for n >= 1, where B(n) = Bernoulli(n, 0). - Peter Luschny, May 18 2023

A001898 Denominators of Bernoulli polynomials B(n)(x).

Original entry on oeis.org

1, 2, 12, 8, 240, 96, 4032, 1152, 34560, 7680, 101376, 18432, 50319360, 7741440, 6635520, 884736, 451215360, 53084160, 42361159680, 4459069440, 1471492915200, 140142182400, 1758147379200, 152882380800, 417368899584000, 33389511966720, 15410543984640
Offset: 0

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Author

Keywords

Examples

			The Bernoulli polynomials B(0)(x) through B(6)(x) are:
1;
-(1/2)*x;
(1/12)*(3*x-1)*x;
-(1/8)*(x-1)*x^2;
(1/240)*(15*x^3-30*x^2+5*x+2)*x;
-(1/96)*(x-1)*(3*x^2-7*x-2)*x^2;
(1/4032)*(63*x^5-315*x^4+315*x^3+91*x^2-42*x-16)*x.
		

References

  • F. N. David, Probability Theory for Statistical Methods, Cambridge, 1949; see pp. 103-104. [There is an error in the recurrence for B_s^{(r)}.]
  • N. E. Nørlund, Vorlesungen über Differenzenrechnung. Springer-Verlag, Berlin, 1924, p. 459.
  • 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

Programs

  • Maple
    B:=bernoulli; b:=proc(s) option remember; local t; global r; if s=0 then RETURN(1); fi; expand((-r/s)*add( (-1)^t*binomial(s,t)*B(t)*b(s-t),t=1..s)); end; [seq(denom(b(n)),n=0..30)];
  • Mathematica
    B[s_] := B[s] = If[s == 0, 1, (-x/s)*Sum[(-1)^t*Binomial[s, t]*
       BernoulliB[t]*B[s - t], {t, 1, s}]] // Factor;
    a[n_] := If[n == 0, 1, B[n] // First // Denominator];
    Table[a[n], {n, 0, 26}] (* Jean-François Alcover, Jul 24 2022 *)

Formula

These Bernoulli polynomials B(s) = B(s)(x) are defined by: B(0) = 1; B(s) = (-x/s)*Sum_{t=1..s} (-1)^t*binomial(s, t)*Bernoulli(t)*B(s-t), where Bernoulli(t) are the usual Bernoulli numbers A027641/A027642. Also B(s)(1) = Bernoulli(s).

Extensions

Entry revised Dec 03 2004

A100655 Triangle read by rows giving coefficients in Bernoulli polynomials as defined in A001898, after multiplication by the common denominators A001898(n).

Original entry on oeis.org

1, 0, -1, 0, -1, 3, 0, 0, 1, -1, 0, 2, 5, -30, 15, 0, 0, -2, -5, 10, -3, 0, -16, -42, 91, 315, -315, 63, 0, 0, 16, 42, -7, -105, 63, -9, 0, 144, 404, -540, -2345, -840, 3150, -1260, 135, 0, 0, -144, -404, -100, 665, 448, -630, 180, -15, 0, -768, -2288, 2068, 11792, 8195, -8085, -8778, 6930, -1485, 99
Offset: 0

Views

Author

N. J. A. Sloane, Dec 05 2004

Keywords

Comments

Let p(n, x) = Sum_{k=0..n} T(n, k)*x^k, then the polynomials (-1)^n*p(n; x)/x are called 'Stirling polynomials' by Knuth et al. (CMath, eq. 6.45). - Peter Luschny, Feb 05 2021

Examples

			The Bernoulli polynomials B(0)(x) through B(6)(x) are:
        1
    -(1/2)* x
    (1/12)*(3*x - 1)*x
    -(1/8)*(x-1)*x^2
   (1/240)*(15*x^3 - 30*x^2 + 5*x + 2)*x
   -(1/96)*(x-1)*(3*x^2 - 7*x - 2)*x^2
  (1/4032)*(63*x^5 - 315*x^4 + 315*x^3 + 91*x^2 - 42*x - 16)*x
Triangle of coefficients starts:
[0] [1],
[1] [0,  -1],
[2] [0,  -1,   3],
[3] [0,   0,   1,   -1],
[4] [0,   2,   5,  -30,    15],
[5] [0,   0,  -2,   -5,    10,   -3],
[6] [0, -16, -42,   91,   315, -315,   63],
[7] [0,   0,  16,   42,    -7, -105,   63,    -9],
[8] [0, 144, 404, -540, -2345, -840, 3150, -1260, 135].
		

References

  • Ronald L. Graham, Donald E. Knuth and Oren Patashnik, Concrete Math., 1st ed.; Addison-Wesley, 1989, p. 257.

Crossrefs

Programs

  • Maple
    CoeffList := p -> op(PolynomialTools:-CoefficientList(simplify(p),x)):
    E2 := (n, k) -> combinat[eulerian2](n, k): m := n -> mul(j-x, j = 1..n):
    Epoly := n -> simplify(expand(add(E2(n, k)*binomial(x+k,2*n), k = 0..n)/m(n))):
    poly := n -> Epoly(n)*denom(Epoly(n)):
    seq(print(CoeffList(poly(n))), n = 0..8); # Peter Luschny, Feb 05 2021
  • Mathematica
    row[n_] := NorlundB[n, x] // Together // Numerator // CoefficientList[#, x]&; Table[row[n], {n, 0, 10}] // Flatten (* Jean-François Alcover, Jul 06 2019, after Peter Luschny *)
  • Sage
    # Formula (83), page 146 in Nörlund.
    @cached_function
    def NoerlundB(n, x):
        if n == 0: return 1
        return expand((-x/n)*add((-1)^k*binomial(n,k)*bernoulli(k)*NoerlundB(n-k,x) for k in (1..n)))
    def A100655_row(n): return numerator(NoerlundB(n, x)).list()
    [A100655_row(n) for n in (0..8)] # Peter Luschny, Jul 01 2019

Formula

E.g.f.: (y/(exp(y)-1))^x. - Vladeta Jovovic, Feb 27 2006
Let p(n, x) = (Sum_{k=0..n} E2(n, k)*binomial(x + k, 2*n))/(Product_{j=1..n} (j-x)), where E2 are the second-order Eulerian numbers (A201637), then T(n, k) = [x^k] M(n+1)*p(n, x), where M(n) are the Minkowski numbers (A053657). - Peter Luschny, Feb 05 2021

A197419 Triangle with the numerator of the coefficient [x^k] of the second order Bernoulli polynomial B_n^(2)(x) in row n, column 0<=k<=n.

Original entry on oeis.org

1, -1, 1, 5, -2, 1, -1, 5, -3, 1, 1, -2, 5, -4, 1, 1, 1, -5, 25, -5, 1, -5, 1, 3, -10, 25, -6, 1, -1, -5, 7, 7, -35, 35, -7, 1, 7, -4, -10, 28, 7, -28, 70, -8, 1, 3, 21, -6, -10, 21, 63, -42, 30, -9, 1, -15, 3, 21, -20, -25, 42, 21, -60, 75, -10, 1, -5, -15, 33, 77, -55, -55, 77, 33, -165, 275, -11, 1, 7601, -10, -45, 66, 231, -132, -110, 132, 99, -110, 55, -12, 1
Offset: 0

Views

Author

R. J. Mathar, Oct 14 2011

Keywords

Comments

The a-th order Bernoulli polynomials are defined via the exponential generating function (t/(exp t -1))^a*exp(x*t) = sum_{n>=0} B_n^(a)(x) * t^n/n!. The current triangular array shows the coefficient [x^k] of B_n^(2)(x), i.e. the expansion coefficients in rising powers of the polynomial of x with a=2.
P(n,x) = x^n + 2*Sum_{m=0..n-1} binomial(n,m)*x^m*Sum_{k=1..n-m} stirling2(n-m,k)*stirling1(2+k,2)/((k+1)*(k+2)). - Vladimir Kruchinin, Oct 23 2011

Examples

			The table of the coefficients is
  1;
  -1,1;
  5/6,-2,1;     5/6-2x+x^2
  -1/2,5/2,-3,1;   -1/2+5x/2-3x^2+x^3
  1/10,-2,5,-4,1;
  1/6,1/2,-5,25/3,-5,1;
  -5/42,1,3/2,-10,25/2,-6,1;
  -1/6,-5/6,7/2,7/2,-35/2,35/2,-7,1;
  7/30,-4/3,-10/3,28/3,7,-28,70/3,-8,1;
  3/10,21/10,-6,-10,21,63/5,-42,30,-9,1;
  -15/22,3,21/2,-20,-25,42,21,-60,75/2,-10,1;
  -5/6,-15/2,33/2,77/2,-55,-55,77,33,-165/2,275/6,-11,1;
  7601/2730,-10,-45,66,231/2,-132,-110,132,99/2,-110,55,-12,1;
		

Crossrefs

Cf. A197420 (denominator), A100616, A100615 (column k=0).

Programs

  • Maple
    A197419 := proc(n,k)
            local a,Bt,Bnx,o ,t,x;
            a := 2 ;
            Bt := (t/(exp(t)-1))^a*exp(x*t) ;
            Bnx := n!*coeftayl(Bt,t=0,n) ;
            coeftayl(Bnx,x=0,k) ;
            numer(%) ;
    end proc:
    seq(seq(A197419(n,k),k=0..n),n=0..4) ; # print row by row
  • Mathematica
    t[n_, m_] := If [n == m, 1, 2*Binomial[n, m]*Sum[StirlingS2[n-m, k]*StirlingS1[2+k, 2]/((k+1)*(2+k)), {k, 1, n-m}]]; Table[t[n, m] // Numerator, {n, 0, 12}, {m, 0, n}] // Flatten (* Jean-François Alcover, Dec 12 2013, after Vladimir Kruchinin *)
  • Maxima
    T(n,m):=num(if n=m then 1 else 2*binomial(n,m)* sum(stirling2(n-m,k) *stirling1(2+k,2)/ ((k+1)*(2+k)),k,1,n-m)); /* Vladimir Kruchinin, Oct 23 2011 */

Formula

T(n,m) = 2*binomial(n,m)*Sum_{k=1..n-m} Stirling2(n-m,k)*Stirling1(2+k,2)/((k+1)*(k+2)), mVladimir Kruchinin, Oct 23 2011
Showing 1-4 of 4 results.