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 1-3 of 3 results.

A183066 G.f.: A(x) = (1 + 21*x + 3*x^2 - x^3)/(1-x)^5.

Original entry on oeis.org

1, 26, 123, 364, 845, 1686, 3031, 5048, 7929, 11890, 17171, 24036, 32773, 43694, 57135, 73456, 93041, 116298, 143659, 175580, 212541, 255046, 303623, 358824, 421225, 491426, 570051, 657748, 755189, 863070, 982111, 1113056, 1256673, 1413754, 1585115, 1771596
Offset: 0

Views

Author

Paul D. Hanna, Dec 22 2010

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=polcoeff((1+21*x+3*x^2-x^3)/(1-x+x*O(x^n))^5,n)}

Formula

a(n) = A183065(n+1,1).

A183065 Triangle defined by g.f.: Sum_{n>=0} (4*n)!/n!^4 * x^(2*n)*y^n/(1-x-x*y)^(4*n+1), read by rows.

Original entry on oeis.org

1, 1, 1, 1, 26, 1, 1, 123, 123, 1, 1, 364, 3246, 364, 1, 1, 845, 25210, 25210, 845, 1, 1, 1686, 120135, 606500, 120135, 1686, 1, 1, 3031, 430941, 6082475, 6082475, 430941, 3031, 1, 1, 5048, 1277668, 38698856, 137915470, 38698856, 1277668, 5048, 1, 1, 7929
Offset: 0

Views

Author

Paul D. Hanna, Dec 22 2010

Keywords

Comments

Compare the g.f. of this triangle with the g.f.s of triangles:
* A008459: Sum_{n>=0} (2n)!/n!^2 * x^(2n)*y^n/(1-x-xy)^(2n+1),
* A181543: Sum_{n>=0} (3n)!/n!^3 * x^(2n)*y^n/(1-x-xy)^(3n+1),
which have terms A008459(n,k) = C(n,k)^2 and A181543(n,k) = C(n,k)^3.

Examples

			G.f.: A(x,y) = 1/(1-x-xy) + 4!*x^2*y/(1-x-xy)^5 + (8!/2!^4)*x^4*y^2/(1-x-xy)^9 + (12!/3!^4)*x^6*y^3/(1-x-xy)^13 +...
Triangle begins:
1;
1, 1;
1, 26, 1;
1, 123, 123, 1;
1, 364, 3246, 364, 1;
1, 845, 25210, 25210, 845, 1;
1, 1686, 120135, 606500, 120135, 1686, 1;
1, 3031, 430941, 6082475, 6082475, 430941, 3031, 1;
1, 5048, 1277668, 38698856, 137915470, 38698856, 1277668, 5048, 1; ...
		

Crossrefs

Cf. A183066 (column 1), A183067 (row sums), A183068 (central terms).

Programs

  • PARI
    {T(n,k)=polcoeff(polcoeff(sum(m=0,n,(4*m)!/m!^4*x^(2*m)*y^m/(1-x-x*y+x*O(x^n))^(4*m+1)),n,x),k,y)}

A183067 G.f.: A(x) = Sum_{n>=0} (4n)!/n!^4 * x^(2n)/(1-2*x)^(4n+1).

Original entry on oeis.org

1, 2, 28, 248, 3976, 52112, 850144, 13032896, 217878616, 3594283952, 61577419168, 1056910842176, 18485891235904, 325146542386304, 5781811796793088, 103413141115923968, 1863085674077321176, 33737014083314312624
Offset: 0

Views

Author

Paul D. Hanna, Dec 22 2010

Keywords

Crossrefs

Programs

  • PARI
    {a(n)=polcoeff(sum(m=0,n,(4*m)!/m!^4*x^(2*m)/(1-2*x+x*O(x^n))^(4*m+1)),n)}

Formula

Row sums of triangle A183065.
Showing 1-3 of 3 results.