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.

A370234 a(n) = hypergeom([-n, 1 + n, 2 + n, -1 - n], [1/2, 1/2, 1], 1/16). Row sums of A370233.

Original entry on oeis.org

1, 4, 24, 143, 881, 5534, 35213, 226238, 1464382, 9534594, 62377881, 409717004, 2700168229, 17845927498, 118238842174, 785086422265, 5222747607607, 34802614713382, 232261844100109, 1552139710253683, 10385180872126402, 69563083672190704, 466425975579323539
Offset: 0

Views

Author

Peter Luschny, Feb 13 2024

Keywords

Crossrefs

Cf. A370233.

Programs

  • Mathematica
    Table[HypergeometricPFQ[{-1 - n, -n, 1 + n, 2 + n}, {1/2, 1/2, 1}, 1/16], {n, 0, 25}] (* Vaclav Kotesovec, Feb 18 2024 *)
  • PARI
    a(n) = round(hypergeom([-n, 1 + n, 2 + n, -1 - n], [1/2, 1/2, 1], 1/16)); \\ Michel Marcus, Feb 13 2024

Formula

a(n) ~ phi^(4*n+4) / (2^(3/2) * 5^(1/4) * sqrt(Pi*n)), where phi = A001622 is the golden ratio. - Vaclav Kotesovec, Feb 18 2024

A370232 Triangle read by rows. T(n, k) = binomial(n + k, 2*k)^2.

Original entry on oeis.org

1, 1, 1, 1, 9, 1, 1, 36, 25, 1, 1, 100, 225, 49, 1, 1, 225, 1225, 784, 81, 1, 1, 441, 4900, 7056, 2025, 121, 1, 1, 784, 15876, 44100, 27225, 4356, 169, 1, 1, 1296, 44100, 213444, 245025, 81796, 8281, 225, 1, 1, 2025, 108900, 853776, 1656369, 1002001, 207025, 14400, 289, 1
Offset: 0

Views

Author

Peter Luschny, Feb 12 2024

Keywords

Examples

			Triangle starts:
[0] 1;
[1] 1,     1;
[2] 1,     9,       1;
[3] 1,    36,      25,       1;
[4] 1,   100,     225,      49,       1;
[5] 1,   225,    1225,     784,      81,      1;
[6] 1,   441,    4900,    7056,    2025,    121,     1;
[7] 1,   784,   15876,   44100,   27225,   4356,   169,   1;
		

Crossrefs

Shifted bisection of A182878.
Cf. A370233 (c=2), A188648 (row sums), A188662 (central terms).

Programs

  • Mathematica
    Table[Binomial[n + k, 2*k]^2, {n, 0, 7}, {k, 0, n}] // Flatten

Formula

T(n, k) = [z^k] P(n, z) where P(n, z) = Sum_{k=0..n} binomial(n + k, 2*k) * Pochhammer(n - k + c, 2*k) * z^k / (2*k)! and c = 1.
T(n, k) = [z^k] hypergeom([-n, -n, 1 + n, 1 + n], [1/2, 1/2, 1], z/16).
Showing 1-2 of 2 results.