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 1-2 of 2 results.

A327416 a(n) = A156289(2*n, n).

Original entry on oeis.org

1, 1, 63, 21120, 20585565, 44025570225, 175418438510700, 1169944052730453000, 12110024900113702687125, 183906442861089163922581875, 3923248989041777334572795737575, 113570018319217734510803494872644700, 4337118170117525113961286942555563803500
Offset: 0

Views

Author

Peter Luschny, Sep 14 2019

Keywords

Crossrefs

Cf. A007820 (m=1), this sequence (m=2), A327417 (m=3), A327418 (m=4).
Associated triangles: A048993 (m=1), A156289 (m=2), A291451 (m=3), A291452 (m=4).

Programs

  • SageMath
    @cached_function
    def P(m, n):
        x = polygen(ZZ)
        if n == 0: return x^0
        return expand(sum(binomial(m*n, m*k)*P(m, n-k)*x for k in (1..n)))
    def A327416(n): return P(2, 2*n).list()[n]//factorial(n)
    print([A327416(n) for n in range(13)])

A327417 a(n) = A291451(2*n, n).

Original entry on oeis.org

1, 1, 682, 7128576, 429120851544, 94066556834970720, 57496301859366489159040, 82247725949165261902606309120, 243263294602173417290925789755652480, 1356449073308047884259226117174893156252800, 13275987570857688650109290727617026478737341900800
Offset: 0

Views

Author

Peter Luschny, Sep 14 2019

Keywords

Crossrefs

Cf. A007820 (m=1), A327416 (m=2), this sequence (m=3), A327418 (m=4).
Associated triangles: A048993 (m=1), A156289 (m=2), A291451 (m=3), A291452 (m=4).

Programs

  • Sage
    # uses[P from A327416]
    def A327417(n): return P(3, 2*n).list()[n]//factorial(n)
    print([A327417(n) for n in range(11)])
Showing 1-2 of 2 results.