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 1-3 of 3 results.

A081041 6th binomial transform of (1,5,0,0,0,0,0,0,...).

Original entry on oeis.org

1, 11, 96, 756, 5616, 40176, 279936, 1912896, 12877056, 85660416, 564350976, 3688436736, 23944605696, 154551545856, 992612745216, 6347497291776, 40435908673536, 256721001578496, 1624959306694656, 10257555623510016
Offset: 0

Views

Author

Paul Barry, Mar 04 2003

Keywords

Crossrefs

Programs

  • Magma
    [(5*n+6)*6^(n-1): n in [0..25]]; // Vincenzo Librandi, Aug 06 2013
  • Mathematica
    CoefficientList[Series[(1 - x)/(1 - 6 x)^2, {x, 0, 30}], x] (* Vincenzo Librandi, Aug 06 2013 *)
    LinearRecurrence[{12,-36},{1,11},20] (* Harvey P. Dale, Mar 04 2019 *)

Formula

a(n) = 12*a(n-1) - 36*a(n-2) for n>1, a(0)=1, a(1)=9.
a(n) = (5*n+6)*6^(n-1).
a(n) = Sum_{k=0..n} (k+1)*5^k*binomial(n, k).
G.f.: (1-x)/(1-6*x)^2.
E.g.f.: exp(6*x)*(1 + 5*x). - Stefano Spezia, Jan 31 2025

A081043 8th binomial transform of (1,7,0,0,0,0,0,...).

Original entry on oeis.org

1, 15, 176, 1856, 18432, 176128, 1638400, 14942208, 134217728, 1191182336, 10468982784, 91268055040, 790273982464, 6803228196864, 58274116272128, 496979255754752, 4222124650659840, 35747322042253312, 301741175033823232
Offset: 0

Views

Author

Paul Barry, Mar 04 2003

Keywords

Crossrefs

Programs

  • Magma
    I:=[1, 15]; [n le 2 select I[n] else 16*Self(n-1)-64*Self(n-2): n in [1..30]]; // Vincenzo Librandi, Feb 23 2012
  • Mathematica
    LinearRecurrence[{16,-64},{1,15},20] (* or *) Table[(7n+8)8^(n-1),{n,0,20}] (* Harvey P. Dale, Feb 22 2012 *)

Formula

a(n) = 16*a(n-1) - 64*a(n-2), a(0)=1, a(1)=15.
a(n) = (7n+8)*8^(n-1).
a(n) = Sum_{k=0..n} (k+1)*7^k*binomial(n, k).
G.f.: (1-x)/(1-8*x)^2.
E.g.f.: exp(8*x)*(1 + 7*x). - Stefano Spezia, Jan 31 2025

A380747 Array read by ascending antidiagonals: A(n,k) = [x^n] (1 - x)/(1 - k*x)^2.

Original entry on oeis.org

1, -1, 1, 0, 1, 1, 0, 1, 3, 1, 0, 1, 8, 5, 1, 0, 1, 20, 21, 7, 1, 0, 1, 48, 81, 40, 9, 1, 0, 1, 112, 297, 208, 65, 11, 1, 0, 1, 256, 1053, 1024, 425, 96, 13, 1, 0, 1, 576, 3645, 4864, 2625, 756, 133, 15, 1, 0, 1, 1280, 12393, 22528, 15625, 5616, 1225, 176, 17, 1
Offset: 0

Views

Author

Stefano Spezia, Jan 31 2025

Keywords

Examples

			The array begins as:
   1, 1,   1,    1,     1,     1, ...
  -1, 1,   3,    5,     7,     9, ...
   0, 1,   8,   21,    40,    65, ...
   0, 1,  20,   81,   208,   425, ...
   0, 1,  48,  297,  1024,  2625, ...
   0, 1, 112, 1053,  4864, 15625, ...
   0, 1, 256, 3645, 22528, 90625, ...
   ...
		

Crossrefs

Cf. A000012 (k=1 or n=0), A000567 (n=2), A001792 (k=2), A007778, A060747 (n=1), A081038 (k=3), A081039 (k=4), A081040 (k=5), A081041 (k=6), A081042 (k=7), A081043 (k=8), A081044 (k=9), A081045 (k=10), A103532, A154955, A380748 (antidiagonal sums).

Programs

  • Mathematica
    A[0,0]:=1; A[1,0]:=-1; A[n_,k_]:=((k-1)*n+k)k^(n-1); Table[A[n-k,k],{n,0,10},{k,0,n}]//Flatten (* or *)
    A[n_,k_]:=SeriesCoefficient[(1-x)/(1-k*x)^2,{x,0,n}]; Table[A[n-k,k],{n,0,10},{k,0,n}]//Flatten (* or *)
    A[n_,k_]:=n!SeriesCoefficient[Exp[k*x](1+(k-1)*x),{x,0,n}]; Table[A[n-k,k],{n,0,10},{k,0,n}]//Flatten

Formula

A(n,k) = ((k - 1)*n + k)*k^(n-1) with A(0,0) = 1.
A(n,k) = n! * [x^n] exp(k*x)*(1 + (k - 1)*x).
A(n,0) = A154955(n+1).
A(3,n) = A103532(n-1) for n > 0.
A(n,n) = A007778(n) for n > 0.
Showing 1-3 of 3 results.