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.

A362995 Triangle read by rows. T(n, k) = [x^k] lcm({i + 1 : 0 <= i <= n}) * (Sum_{u=0..k} ( Sum_{j=0..u} x^j * binomial(u, j) * (j + 1)^n ) / (u + 1)).

Original entry on oeis.org

1, 3, 2, 11, 28, 18, 25, 184, 351, 192, 137, 2608, 11097, 16128, 7500, 147, 6816, 57591, 166912, 193750, 77760, 1089, 118464, 1865511, 9588736, 20843750, 20062080, 7058940, 2283, 567936, 16015401, 136921088, 495546875, 858003840, 704129265, 220200960
Offset: 0

Views

Author

Peter Luschny, May 14 2023

Keywords

Examples

			Triangle T(n, k) starts:
[0]    1;
[1]    3,      2;
[2]   11,     28,       18;
[3]   25,    184,      351,       192;
[4]  137,   2608,    11097,     16128,      7500;
[5]  147,   6816,    57591,    166912,    193750,     77760;
[6] 1089, 118464,  1865511,   9588736,  20843750,  20062080,   7058940;
[7] 2283, 567936, 16015401, 136921088, 495546875, 858003840, 704129265, 220200960;
		

Crossrefs

Cf. A362993 (row sums), A362994 (alternating row sums), A001008 (column 0), A362992 (main diagonal), A362996/A362997.
Cf. A363000.

Programs

  • Maple
    R := (n, x) -> add(add(x^j*binomial(u, j)*(j + 1)^n, j = 0..u)/(u + 1), u=0..n):
    CoeffList := p -> PolynomialTools:-CoefficientList(p, x):
    poly := (n, x) -> ilcm(seq(i, i = 1..n+1)) * R(n, x):
    seq(print(CoeffList(poly(n, x))), n = 0..7);
  • SageMath
    def A362995row(n: int) -> list[int]:
        s = add((1 / (u + 1)) * add(x^j * binomial(u, j) * (j + 1)^n
            for j in (0..u)) for u in (0..n))
        l = lcm(i + 1 for i in (0..n))
        return (s * l).list()
    for n in (0..7): print(A362995row(n))

Formula

T(n, k) = lcm(1,2, ..., n+1) * A362996(n, k) / A362997(n, k).
Sum_{k=0..n} (-1)^k * T(n, k) = lcm(1,2, ..., n+1) * Bernoulli(n, 1) = A362994(n).