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.

Previous Showing 11-13 of 13 results.

A379378 The n-th term of the n-th forward differences of partition numbers A000041.

Original entry on oeis.org

1, 1, 1, 2, 5, 10, 22, 64, 159, 328, 747, 1914, 4608, 10252, 23339, 55405, 128034, 287855, 660549, 1541383, 3528645, 7921187, 17870633, 40689873, 92248847, 207911243, 469331387, 1059603243, 2377923972, 5313383490, 11889346697, 26641635997, 59560543885
Offset: 0

Views

Author

Alois P. Heinz, Dec 21 2024

Keywords

Crossrefs

Main diagonal of A175804.
Cf. A000041, A033815, A281425, A386457 (parity).

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(k=0,
          combinat[numbpart](n), b(n+1, k-1)-b(n, k-1))
        end:
    a:= n-> b(n$2):
    seq(a(n), n=0..32);
  • Mathematica
    A379378list[nmax_] := Module[{p = PartitionsP[Range[0, nmax*2]]}, Join[{First[p]}, Table[First[p = Differences[Rest[p]]], nmax]]];
    A379378list[50] (* Paolo Xausa, Jul 26 2025 *)

A338152 a(n) is the number of acyclic orientations of the edges of an n-dimensional demihypercube.

Original entry on oeis.org

1, 2, 24, 24024, 193270310, 767795414400
Offset: 1

Views

Author

Peter Kagey, Oct 13 2020

Keywords

Crossrefs

Cf. A033815 (cross-polytope), A058809 (wheel), A334247 (hypercube), A338153 (prism), A338154 (antiprism).

Programs

  • Mathematica
    Table[Abs[ChromaticPolynomial[GraphData[{"HalvedCube",n}]][-1]],{n,1,6}]

Formula

a(n) = |Sum_{k=0..2^(n-1)} (-1)^k * A334280(n, k)|.

A116854 First differences of the rows in the triangle of A116853, starting with 0.

Original entry on oeis.org

1, 1, 1, 3, 1, 2, 11, 3, 4, 6, 53, 11, 14, 18, 24, 309, 53, 64, 78, 96, 120, 2119, 309, 362, 426, 504, 600, 720, 16687, 2119, 2428, 2790, 3216, 3720, 4320, 5040, 148329, 16687, 18806, 21234, 24024, 27240, 30960, 35280, 40320, 1468457, 148329, 165016, 183822, 205056, 229080, 256320, 287280, 322560, 362880
Offset: 1

Views

Author

Gary W. Adamson, Feb 24 2006

Keywords

Comments

Row n contains the first differences of row n of A116853, starting with T(n,1) = A116853(n,1) - 0.
As in A116853, 0! = 1 is omitted here. - Georg Fischer, Mar 23 2019

Examples

			First few rows of the triangle are:
[1]    1;
[2]    1,   1;
[3]    3,   1,   2;
[4]   11,   3,   4,   6;
[5]   53,  11,  14,  18,  24;
[6]  309,  53,  64,  78,  96, 120;
[7] 2119, 309, 362, 426, 504, 600, 720;
...
For example, row 4 (11, 3, 4, 6) are first differences along row 4 of A116853: ((0), 11, 14, 18, 24).
		

Crossrefs

Cf. A000142 (row sums), A033815 (central terms), A047920, A068106 (with 0!), A055790 (column k=3), A277609 (k=4), A277563 (k=5), A280425 (k=6).

Programs

  • Haskell
    a116854 n k = a116854_tabl !! (n-1) !! (k-1)
    a116854_row n = a116854_tabl !! (n-1)
    a116854_tabl = [1] : zipWith (:) (tail $ map head tss) tss
                   where tss = a116853_tabl
    -- Reinhard Zumkeller, Aug 31 2014
  • Maple
    A116853 := proc(n,k) option remember ; if n = k then n! ; else procname(n,k+1)-procname(n-1,k) ; end if; end proc:
    A116854 := proc(n,k) if k = 1 then A116853(n,1) ; else A116853(n,k) -A116853(n,k-1) ; end if; end proc:
    seq(seq(A116854(n,k),k=1..n),n=1..15) ; # R. J. Mathar, Mar 27 2010
  • Mathematica
    rows = 10;
    rr = Range[rows]!;
    dd = Table[Differences[rr, n], {n, 0, rows - 1}];
    T = Array[t, {rows, rows}];
    Do[Thread[Evaluate[Diagonal[T, -k+1]] = dd[[k, ;; rows-k+1]]], {k, rows}];
    Table[({0}~Join~Table[t[n, k], {k, 1, n}]) // Differences, {n, 1, rows}] // Flatten (* Jean-François Alcover, Dec 21 2019 *)

Formula

T(n,k) = A116853(n,k) - A116853(n,k-1) if k>1.
T(n,1) = A116853(n,1) = A000255(n-1).
Sum_{k=1..n} T(n,1) = n! = A000142(n).

Extensions

Definition made concrete and sequence extended by R. J. Mathar, Mar 27 2010
Previous Showing 11-13 of 13 results.