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.

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A229676 a(n) = Sum_{k = 0..n} Product_{j = 0..8} C(n+j*k,k).

Original entry on oeis.org

1, 362881, 12504639772801, 1080492192338314694401, 140810184334251776225321193601, 23183593018924832394604719137184142081, 4439414110286267003192333763481728593177802241, 944848564471993704169724618186222285154304912036663681
Offset: 0

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Author

Alois P. Heinz, Sep 27 2013

Keywords

Comments

Number of lattice paths from {n}^9 to {0}^9 using steps that decrement one component or all components by 1.

Crossrefs

Column k = 9 of A229142.

Programs

  • Maple
    with(combinat):
    a:= n-> add(multinomial(n+8*k, n-k, k$9), k=0..n):
    seq(a(n), n=0..10);
  • Mathematica
    multinomial[n_, k_List] := n!/Times @@ (k!); a[n_] := Sum[multinomial[n + 8*k, Join[{n - k}, Array[k&, 9]]], {k, 0, n}]; Table[a[n], {n, 0, 10}] (* Jean-François Alcover, Dec 27 2013, translated from Maple *)

Formula

a(n) = Sum_{k = 0..n} multinomial(n+8*k; n-k, {k}^9).
G.f.: Sum_{k >= 0} (9*k)!/k!^9 * x^k / (1-x)^(9*k+1).
exp( Sum_{n >= 1} a(n)*x^n/n ) = 1 + x + 181441*x^2 + 4168213439041*x^3 + 270123052269252349441*x^4 + ... appears to have integer coefficients. - Peter Bala, Jan 13 2016

A229677 a(n) = Sum_{k = 0..n} Product_{j = 0..9} C(n+j*k,k).

Original entry on oeis.org

1, 3628801, 2375880907276801, 4386797386179342934060801, 12868640117405297821759744777996801, 49120459033702373637913562847507823210617601, 222254155614179529476178258638452174287098861960755201, 1132660294172702489573582429384603543633942385302181948349459201
Offset: 0

Views

Author

Alois P. Heinz, Sep 27 2013

Keywords

Comments

Number of lattice paths from {n}^10 to {0}^10 using steps that decrement one component or all components by 1.

Crossrefs

Column k = 10 of A229142.

Programs

  • Maple
    with(combinat):
    a:= n-> add(multinomial(n+9*k, n-k, k$10), k=0..n):
    seq(a(n), n=0..10);
  • Mathematica
    multinomial[n_, k_List] := n!/Times @@ (k!); a[n_] := Sum[multinomial[n + 9*k, Join[{n - k}, Array[k&, 10]]], {k, 0, n}]; Table[a[n], {n, 0, 10}] (* Jean-François Alcover, Dec 27 2013, translated from Maple *)

Formula

a(n) = Sum_{k = 0..n} multinomial(n+9*k; n-k, {k}^10).
G.f.: Sum_{k >= 0} (10*k)!/k!^10 * x^k / (1-x)^(10*k+1).
exp( Sum_{n >= 1} a(n)*x^n/n ) = 1 + x + 1814401*x^2 + 791960304240001*x^3 + 1096699347338442061435201*x^4 + ... appears to have integer coefficients. - Peter Bala, Jan 13 2016

A336169 Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) = Sum_{j=0..n} (-1)^(n-j) * multinomial(n+(k-1)*j; n-j, {j}^k).

Original entry on oeis.org

1, 1, 0, 1, 0, 1, 1, 1, 0, 0, 1, 5, 1, 0, 1, 1, 23, 67, 1, 0, 0, 1, 119, 2401, 1109, 1, 0, 1, 1, 719, 112681, 347279, 20251, 1, 0, 0, 1, 5039, 7479361, 166923119, 58370761, 391355, 1, 0, 1, 1, 40319, 681040081, 137127810959, 302857024681, 10693893503, 7847155, 1, 0, 0, 1, 362879, 81729285121, 182499151015439, 3244063941457921, 616967236620839, 2071837562929, 161476565, 1, 0, 1
Offset: 0

Views

Author

Seiichi Manyama, Jul 10 2020

Keywords

Comments

Column k is the diagonal of the rational function 1 / (1 - Sum_{j=1..k} x_j + Product_{j=1..k} x_j) for k>0.

Examples

			Square array begins:
  1, 1, 1,      1,           1,               1, ...
  0, 0, 1,      5,          23,             119, ...
  1, 0, 1,     67,        2401,          112681, ...
  0, 0, 1,   1109,      347279,       166923119, ...
  1, 0, 1,  20251,    58370761,    302857024681, ...
  0, 0, 1, 391355, 10693893503, 616967236620839, ...
		

Crossrefs

Columns k=0-5 give: A059841, A000007, A000012, A124435, A336170, A336171.
Rows n=0-1 give: A000012, A033312.
Main diagonal gives A336172.
Cf. A229142.

Programs

  • Mathematica
    T[n_, k_] := Sum[(-1)^(n - j)*(n + (k - 1)*j)!/(n - j)!/(j!)^k, {j, 0, n} ]; Table[T[k, n - k], {n, 0, 10}, {k, 0, n}] // Flatten (* Amiram Eldar, Jul 10 2020 *)

Formula

G.f. of column k: Sum_{j>=0} (k*j)!/j!^k * x^j / (1+x)^(k*j+1).
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