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.

A094074 Coefficients arising in combinatorial field theory.

Original entry on oeis.org

1, 5, 129, 7485, 755265, 116338005, 25263540225, 7328358482445, 2730934406225025, 1269262202389906725, 718835160819268317825, 486853691847850902700125, 388278919916351519293663425
Offset: 0

Views

Author

N. J. A. Sloane, May 01 2004

Keywords

Crossrefs

Programs

  • Mathematica
    a[n_] := (2n)! SeriesCoefficient[(1-x^2)^(-1/2) Exp[2x^2/(1-x^2)], {x, 0, 2n}];
    Table[a[n], {n, 0, 12}] (* Jean-François Alcover, Nov 11 2018 *)

Formula

a(n) = (2n)!/(2^n*n!) * h(2n, 2), with h(n, x) the polynomials in A099174.
E.g.f.: Sum_{n>=0} a(n)*x^(2n)/(2n)! = (1-x^2)^(-1/2) * exp(2x^2/(1-x^2)).

Extensions

Edited and extended by Ralf Stephan, Oct 14 2004.

A094071 Coefficients arising in combinatorial field theory.

Original entry on oeis.org

1, 2, 10, 75, 572, 6293, 92962, 1395180, 25482135, 582310475, 13697614020, 364311810217, 11551145067139, 380339218683310, 13636394439014770, 563142483841155427, 24264229405883569164, 1114389674994185476663
Offset: 0

Views

Author

N. J. A. Sloane, May 01 2004

Keywords

References

  • P. Blasiak, K. A. Penson, A. I. Solomon, A. Horzela and G. E. H. Duchamp, Some useful combinatorial formulas for bosonic operators, J. Math. Phys. 46, 052110 (2005) (6 pages).
  • P. Blasiak, K. A. Penson, A. I. Solomon, A. Horzela and G E. H. Duchamp, Combinatorial field theories via boson normal ordering, preprint, Apr 27 2004.

Crossrefs

Programs

  • Maple
    with(combinat):F:=series(exp(x+x^3/3!),x=0,25): seq((n+1)!*coeff(F,x^(n+1))*bell(n+1),n=0..20);
  • Mathematica
    a[n_] := (n+1)! BellB[n+1] SeriesCoefficient[Exp[x+x^3/3!], {x, 0, n+1}];
    Table[a[n], {n, 0, 17}] (* Jean-François Alcover, Nov 11 2018 *)

Formula

a(n)=(n+1)!*B(n+1)*[x^(n+1)](exp(x+x^3/3!)), where B(n) are the Bell numbers (A000110) - Emeric Deutsch, Nov 23 2004

Extensions

More terms from Emeric Deutsch, Nov 23 2004

A094072 Coefficients arising in combinatorial field theory.

Original entry on oeis.org

1, 6, 50, 615, 10192, 214571, 5544394, 171367020, 6208928376, 259542887975, 12356823485580, 662921411131909, 39714830070598204, 2636484537372437498, 192653800829700013970, 15405383160836582657251
Offset: 0

Views

Author

N. J. A. Sloane, May 01 2004

Keywords

References

  • P. Blasiak, K. A. Penson, A. I. Solomon, A. Horzela and G. E. H. Duchamp, Some useful combinatorial formulas for bosonic operators, J. Math. Phys. 46, 052110 (2005) (6 pages).

Crossrefs

Programs

  • Maple
    with(combinat): seq(bell(n+1)*sum(k^(n+1-k)*binomial(n+1,k),k=1..n+1),n=0..18);
  • Mathematica
    Table[BellB[n+1]Sum[Binomial[n+1,k]k^(n+1-k),{k,n+1}],{n,0,20}] (* Harvey P. Dale, Feb 05 2015 *)

Formula

a(n) = B(n+1)*Sum_{k=1..n+1} binomial(n+1, k)*k^(n+1-k), where B(n) are the Bell numbers (A000110). - Emeric Deutsch, Nov 23 2004
E.g.f.: exp(-1)*Sum_{k>=0} exp(k*x*exp(k*x))/k!. - Vladeta Jovovic, Sep 26 2006

Extensions

More terms from Emeric Deutsch, Nov 23 2004

A094070 a(n) = A000085(n) * A000110(n).

Original entry on oeis.org

1, 4, 20, 150, 1352, 15428, 203464, 3162960, 55405140, 1101298600, 24222234720, 590544046744, 15715973012248, 456341011254560, 14312979247985120, 484253161428902192, 17550722413456774848, 680244627812139042016, 28053748582811428182080, 1228896901162555453603712
Offset: 0

Views

Author

N. J. A. Sloane, May 01 2004

Keywords

Comments

Coefficients arising in combinatorial field theory.

References

  • P. Blasiak, K. A. Penson, A. I. Solomon, A. Horzela and G. E. H. Duchamp, Some useful combinatorial formulas for bosonic operators, J. Math. Phys. 46, 052110 (2005) (6 pages).
  • P. Blasiak, K. A. Penson, A. I. Solomon, A. Horzela and G E. H. Duchamp, Combinatorial field theories via boson normal ordering, preprint, Apr 27 2004.

Crossrefs

Programs

  • Maple
    with(combinat): with(orthopoly): seq((I/sqrt(2))^(n+1)*H(n+1,-I/sqrt(2))*bell(n+1),n=0..17); # Emeric Deutsch, Nov 22 2004
  • Mathematica
    a[n_] := Sum[StirlingS1[n+1, k] 2^k BellB[k, 1/2], {k, 0, n+1}] BellB[n+1];
    Table[a[n], {n, 0, 17}] (* Jean-François Alcover, Aug 07 2018 *)

Formula

a(n) = (i/sqrt(2))^(n+1)*H(n+1, -i/sqrt(2))*Bell(n+1), where i=sqrt(-1), H(n, x) are the Hermite polynomials and Bell(n) are the Bell numbers. - Emeric Deutsch, Nov 22 2004

Extensions

More terms from Ralf Stephan, Oct 14 2004
Showing 1-4 of 4 results.