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.

A136595 Matrix inverse of triangle A136590.

Original entry on oeis.org

1, 0, 1, 0, -1, 1, 0, 7, -3, 1, 0, -61, 31, -6, 1, 0, 751, -375, 85, -10, 1, 0, -11821, 5911, -1350, 185, -15, 1, 0, 226927, -113463, 26341, -3710, 350, -21, 1, 0, -5142061, 2571031, -603246, 87381, -8610, 602, -28, 1, 0, 134341711, -67170855, 15887845, -2346330, 240051, -17766
Offset: 0

Views

Author

Paul D. Hanna, Jan 10 2008

Keywords

Comments

A136590 is the triangle of trinomial logarithmic coefficients.
Column 1 is signed A048287, which is the number of semiorders on n labeled nodes whose incomparability graph is connected.
The Bell transform of (-1)^n*A048287(n+1). For the definition of the Bell transform see A264428. - Peter Luschny, Jan 18 2016

Examples

			Triangle begins:
1;
0, 1;
0, -1, 1;
0, 7, -3, 1;
0, -61, 31, -6, 1;
0, 751, -375, 85, -10, 1;
0, -11821, 5911, -1350, 185, -15, 1;
0, 226927, -113463, 26341, -3710, 350, -21, 1;
0, -5142061, 2571031, -603246, 87381, -8610, 602, -28, 1;
0, 134341711, -67170855, 15887845, -2346330, 240051, -17766, 966, -36, 1; ...
		

Crossrefs

Cf. columns: A048287, A136596, A136597; A136590 (matrix inverse); A136588, A136589.

Programs

  • Maple
    # The function BellMatrix is defined in A264428.
    BellMatrix(n -> (-1)^n*A048287(n+1), 9); # Peter Luschny, Jan 27 2016
  • Mathematica
    BellMatrix[f_Function, len_] := With[{t = Array[f, len, 0]}, Table[BellY[n, k, t], {n, 0, len - 1}, {k, 0, len - 1}]];
    rows = 11;
    M = BellMatrix[Sum[(-1)^(k+1) k! StirlingS2[#+1, k] CatalanNumber[k-1], {k, 1, #+1}]&, rows];
    Table[M[[n, k]], {n, 1, rows}, {k, 1, n}] // Flatten (* Jean-François Alcover, Jun 24 2018, after Peter Luschny *)
  • PARI
    {T(n,k) = if(n
    				
  • PARI
    /* Define Stirling2: */
    {Stirling2(n,k) = n!*polcoeff(((exp(x+x*O(x^n))-1)^k)/k!,n)}
    /* Define Catalan(m,n) = [x^n] C(x)^m: */
    {CATALAN(m,n) = binomial(2*n+m,n) * m/(2*n+m)}
    /* Define this triangle: */
    {T(n,k) = if(n
    				
  • Sage
    # uses[bell_matrix from A264428]
    bell_matrix(lambda n: (-1)^n*A048287(n+1), 10) # Peter Luschny, Jan 18 2016

Formula

T(n,k) = Sum_{i=0..n-1} (-1)^i * (k+i)! * Stirling2(n,k+i) * Catalan(k,i)/k!, where Stirling2(n,k) = A008277(n,k); Catalan(k,i) = C(2i+k,i)*k/(2i+k) = coefficient of x^i in C(x)^k with C(x) = (1-sqrt(1-4x))/(2x).

A136597 Column 3 of triangle A136595.

Original entry on oeis.org

1, -6, 85, -1350, 26341, -603246, 15887845, -473148150, 15723174181, -576826897086, 23157022930405, -1009818279438150, 47533643556874021, -2402218856253008526, 129730266330534913765, -7455932648513351731350, 454377365410347843373861
Offset: 3

Views

Author

Paul D. Hanna, Jan 10 2008

Keywords

Crossrefs

Programs

  • PARI
    a(n)=n!/2!* sum(i=0,n-1,(-1)^i*polcoeff(((exp(x+x*O(x^n))-1)^(3+i)),n)*binomial(2*i+3,i)/(2*i+3))
    
  • PARI
    /* Define Stirling2: */ {Stirling2(n,k)=n!*polcoeff(((exp(x+x*O(x^n))-1)^k)/k!,n)} /* Define Catalan(m,n) = [x^n] C(x)^m: */ {Catalan(m,n)=binomial(2*n+m,n)*m/(2*n+m)} /* Define this sequence: */ {a(n)=sum(i=0,n-1,(-1)^i*(3+i)!*Stirling2(n,3+i)*Catalan(3,i)/3!)}

Formula

a(n) = Sum_{i=0..n-1} (-1)^i*(3+i)!*Stirling2(n,3+i)*Catalan(3,i)/3!, where Stirling2(n,k) = A008277(n,k), Catalan(k,i) = C(2*i+k,i)*k/(2*i+k) = coefficient of x^i in C(x)^k with C(x) = (1-sqrt(1-4x))/(2x).

A136588 a(n) = Sum_{k=0..n} A136595(n,k)*n^k.

Original entry on oeis.org

1, 1, 2, 21, 124, 1880, 20046, 391419, 6195288, 147481299, 3121373690, 87790122816, 2329580861268, 75790954533385, 2415630777959686, 89478235732836705, 3323789119614522416, 138402773923330655700
Offset: 0

Views

Author

Paul D. Hanna, Jan 10 2008

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=sum(k=0,n,if(k==0,0^n,n^k*n!/(k-1)!* sum(i=0,n-1,(-1)^i*polcoeff(((exp(x+x*O(x^n))-1)^(k+i)),n)*binomial(2*i+k,i)/(2*i+k))))}

A136589 a(n) = Sum_{k=0..n} A136595(n,k)*(n+1)^k.

Original entry on oeis.org

1, 2, 6, 44, 345, 4182, 53571, 905144, 16154550, 349976610, 8015743483, 211987872516, 5925745900685, 185188128471374, 6108604964499810, 220403394009702384, 8375181440031684305, 342816825221831030490
Offset: 0

Views

Author

Paul D. Hanna, Jan 10 2008

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=sum(k=0,n,if(k==0,0^n,(n+1)^k*n!/(k-1)!* sum(i=0,n-1,(-1)^i*polcoeff(((exp(x+x*O(x^n))-1)^(k+i)),n)*binomial(2*i+k,i)/(2*i+k))))}
Showing 1-4 of 4 results.