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.

A240561 The main diagonal in the difference table of A240559.

Original entry on oeis.org

0, 1, -10, 178, -5296, 238816, -15214480, 1301989648, -144118832896, 20040052293376, -3419989086092800, 702831038438522368, -171209091176316215296, 48783404012394865985536, -16074763418934659189278720, 6065554251200571899397081088, -2598468976240882751482797162496
Offset: 0

Views

Author

Peter Luschny, Apr 17 2014

Keywords

Examples

			a(n) is the main diagonal in this difference table D(n, k):
[    0,     0,     1,    -3,    -5,    45,    61, -1113, -1385]
[    0,     1,    -2,    -8,    40,   106, -1052, -2498]
[    1,    -1,   -10,    32,   146,  -946, -3550]
[    0,   -11,    22,   178,  -800, -4496]
[  -11,    11,   200,  -622, -5296]
[    0,   211,  -422, -5918]
[  211,  -211, -6340]
[    0, -6551]
[-6551]
D(n, 0) = A240560(n).
D(0, n) = A240559(n).
D(2*n, 0) = (-1)^(n+1)*A147315(2*n, 2).
		

Crossrefs

Programs

  • Maple
    A240561_list := proc(len) local A, m, n, k;
    n := 2*len-1; A := array(0..n, 0..n);
    for m from 0 to n do
       A[m, 0] := euler(m) + 2^(m+1)*euler(m+1,0);
       for k from m-1 by -1 to 0 do
          A[k, m-k] := A[k+1, m-k-1] - A[k, m-k-1]
    od od; [seq(A[k, k], k=0..len-1)] end:
    A240561_list(17);
  • Mathematica
    Table[-Sum[Binomial[n, k]*EulerE[n+k+1], {k, 0, n}],{n,0,20}] (* Vaclav Kotesovec, Apr 06 2015 *)
  • Maxima
    a(n):=-sum(binomial(n,k)*euler(n+k+1),k,0,n); /* Vladimir Kruchinin, Apr 06 2015 */

Formula

a(n) = -Sum_{k=0..n}(C(n,k)*Euler(n+k+1)). - Vladimir Kruchinin, Apr 06 2015
a(n) ~ (-1)^(n+1) * 2^(4*n+9/2) * n^(2*n+3/2) / (exp(2*n) * Pi^(2*n+3/2)). - Vaclav Kotesovec, Apr 06 2015