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 1-5 of 5 results.

A362994 a(n) = lcm(1, 2, ..., n+1) * Bernoulli(n, 1). Alternating row sums of A362995 and A363154.

Original entry on oeis.org

1, 1, 1, 0, -2, 0, 10, 0, -84, 0, 2100, 0, -91212, 0, 420420, 0, -86894808, 0, 12796881240, 0, -123176186952, 0, 33154044803880, 0, -2317852458291480, 0, 114488177740536600, 0, -63580025062953158760, 0, 43435207772044760997000, 0, -2182849703429651931795120
Offset: 0

Views

Author

Peter Luschny, May 14 2023

Keywords

Crossrefs

Cf. A362995 (alternating row sum), A363154 (alternating row sum), A003418 (lcm), A164555/A027642 (Bernoulli), A362991 (column 0).

Programs

  • Maple
    A362994 := n -> ilcm(seq(i + 1, i = 0..n)) * bernoulli(n, 1):
    seq(A362994(n), n = 0..32);
  • Mathematica
    A362994[n_]:=LCM@@Range[n+1]BernoulliB[n, 1];Array[A362994,50,0] (* Paolo Xausa, Aug 09 2023 *)
  • PARI
    a(n) = lcm([1..n+1])*subst(bernpol(n), 'x, 1); \\ Michel Marcus, Aug 09 2023

Formula

a(n) = LCM(n) * Sum_{j=0..n} (-1)^(n - j) * j! * Stirling2(n, j) / (j + 1), where LCM(n) = lcm(i + 1, i = 0..n).

A362992 a(n) = (n + 1)^(n - 1) * lcm{k + 1 : 0 <= k <= n}. Main diagonal of triangle A362995.

Original entry on oeis.org

1, 2, 18, 192, 7500, 77760, 7058940, 220200960, 12053081880, 252000000000, 65362309994520, 1716349336289280, 645822919595173320, 20430218263561666560, 701330854833984375000, 51933349175015422033920, 35071094208630625451626320, 1487906280482935955379978240
Offset: 0

Views

Author

Peter Luschny, May 15 2023

Keywords

Crossrefs

Programs

  • Mathematica
    A362992[n_]:=LCM@@Range[n+1](n+1)^(n-1);Array[A362992,20,0] (* Paolo Xausa, Aug 09 2023 *)
  • PARI
    a(n) = (n + 1)^(n - 1) * lcm(vector(n, k, k+1)); \\ Michel Marcus, May 20 2023
  • SageMath
    def A362992(n: int) -> int:
        return (n + 1)^(n - 1) * lcm(k + 1 for k in (0..n))
    print([A362992(n) for n in (0..17)])
    

Formula

a(n) = A362995(n, n).

A362993 Row sums of A362995.

Original entry on oeis.org

1, 5, 139, 8920, 3140313, 386431752, 514497175965, 279843094350688, 309269596069652505, 148299194161602748000, 987531598214016848643771, 736658715557644007659575408, 8631341032315887149556551616665, 9247541236236479803404967113812944, 11617153578430950909883928682002963745
Offset: 0

Views

Author

Peter Luschny, May 14 2023

Keywords

Crossrefs

Cf. A362995.

A362996 Triangle read by rows. T(n, k) = numerator([x^k] R(n, n, x)), where R(n, k, x) = 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, 1, 11, 14, 3, 25, 46, 117, 16, 137, 652, 3699, 1344, 125, 49, 568, 19197, 41728, 19375, 1296, 363, 9872, 621837, 2397184, 2084375, 334368, 16807, 761, 23664, 5338467, 17115136, 99109375, 7150032, 6705993, 262144
Offset: 0

Views

Author

Peter Luschny, May 13 2023

Keywords

Examples

			The triangle T(n, k) begins:
[0]   1;
[1]   3,     1;
[2]  11,    14,       3;
[3]  25,    46,     117,       16;
[4] 137,   652,    3699,     1344,      125;
[5]  49,   568,   19197,    41728,    19375,    1296;
[6] 363,  9872,  621837,  2397184,  2084375,  334368,   16807;
[7] 761, 23664, 5338467, 17115136, 99109375, 7150032, 6705993, 262144;
.
The first few polynomials are:
[0]      1
[1]      x   +      3/2
[2]    3*x^2 +    (14/3)*x   +      11/6
[3]   16*x^3 +   (117/4)*x^2 +     (46/3)*x   +     25/12
[4]  125*x^4 +  (1344/5)*x^3 +  (3699/20)*x^2 +   (652/15)*x   + 137/60
[5] 1296*x^5 + (19375/6)*x^4 + (41728/15)*x^3 + (19197/20)*x^2 + (568/5)*x + 49/20
		

Crossrefs

Cf. A362997 (denominator), A001008 (column 0), A000272 (main diagonal), A362995.

Programs

  • SageMath
    def R(n, k, x):
        return add((1 / (u + 1)) * add(x^j * binomial(u, j) * (j + 1)^n
               for j in (0..u)) for u in (0..k))
    def A362996row(n: int) -> list[int]:
        return [r.numerator() for r in R(n, n, x).list()]
    for n in (0..7): print(A362996row(n))

Formula

T(n, k) = A362995(n, k) * A362997(n, k) / lcm(1, 2, ..., n+1).

A362997 Triangle read by rows. T(n, k) = denominator([x^k] R(n, n, x)), where R(n, k, x) = Sum_{u=0..k} ( Sum_{j=0..u} x^j * binomial(u, j) * (j + 1)^n ) / (u + 1).

Original entry on oeis.org

1, 2, 1, 6, 3, 1, 12, 3, 4, 1, 60, 15, 20, 5, 1, 20, 5, 20, 15, 6, 1, 140, 35, 140, 105, 42, 7, 1, 280, 35, 280, 105, 168, 7, 8, 1, 2520, 315, 280, 315, 504, 7, 72, 9, 1, 2520, 315, 280, 315, 504, 35, 360, 45, 10, 1, 27720, 3465, 3080, 3465, 5544, 385, 3960, 495, 110, 11, 1
Offset: 0

Views

Author

Peter Luschny, May 13 2023

Keywords

Examples

			Triangle T(n, k) starts:
[0]    1;
[1]    2,   1;
[2]    6,   3,   1;
[3]   12,   3,   4,   1;
[4]   60,  15,  20,   5,   1;
[5]   20,   5,  20,  15,   6,  1;
[6]  140,  35, 140, 105,  42,  7,   1;
[7]  280,  35, 280, 105, 168,  7,   8,  1;
[8] 2520, 315, 280, 315, 504,  7,  72,  9,  1;
[9] 2520, 315, 280, 315, 504, 35, 360, 45, 10, 1;
		

Crossrefs

Cf. A362996 (numerator), A002805 (column 0), A362995.

Programs

  • SageMath
    def R(n, k, x):
        return add((1 / (u + 1)) * add(x^j * binomial(u, j) * (j + 1)^n
               for j in (0..u)) for u in (0..k))
    def A362997row(n: int) -> list[int]:
        return [r.denominator() for r in R(n, n, x).list()]
    for n in (0..9): print(A362997row(n))

Formula

T(n, k) = lcm(1, 2, ..., n+1) * A362996(n, k) / A362995(n, k).
Showing 1-5 of 5 results.