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.

A178122 Triangle T(n,m) = A060187(n+1,m+1) + 2*binomial(n,m) - 2, read by rows.

Original entry on oeis.org

1, 1, 1, 1, 8, 1, 1, 27, 27, 1, 1, 82, 240, 82, 1, 1, 245, 1700, 1700, 245, 1, 1, 732, 10571, 23586, 10571, 732, 1, 1, 2191, 60697, 259791, 259791, 60697, 2191, 1, 1, 6566, 331666, 2485398, 4675152, 2485398, 331666, 6566, 1, 1, 19689, 1756410, 21708138, 69413544, 69413544, 21708138, 1756410, 19689, 1
Offset: 0

Views

Author

Roger L. Bagula, May 20 2010

Keywords

Examples

			Rows n>=0 and columns 0<=m<=n start as:
  1;
  1,     1;
  1,     8,       1;
  1,    27,      27,        1;
  1,    82,     240,       82,        1;
  1,   245,    1700,     1700,      245,        1;
  1,   732,   10571,    23586,    10571,      732,        1;
  1,  2191,   60697,   259791,   259791,    60697,     2191,       1;
  1,  6566,  331666,  2485398,  4675152,  2485398,   331666,    6566,     1;
  1, 19689, 1756410, 21708138, 69413544, 69413544, 21708138, 1756410, 19689, 1;
		

Crossrefs

Programs

  • Magma
    A060187:= func< n,k | (&+[(-1)^(k-j)*Binomial(n, k-j)*(2*j-1)^(n-1): j in [1..k]]) >;
    A178122:= func< n,k | A060187(n+1, k+1) + 2*Binomial(n, k) - 2 >;
    [A178122(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Mar 18 2022
    
  • Mathematica
    p[x_, n_] = (1 - x)^(n + 1)*Sum[(2*k + 1)^n*x^k, {k, 0, Infinity}];
    f[n_, m_] := CoefficientList[FullSimplify[ExpandAll[p[x, n]]], x][[m + 1]];
    t[n_, m_] := f[n, m] + 2*Binomial[n, m] - 2 ;
    Table[Table[t[n, m], {m, 0, n}], {n, 0, 10}];
    Flatten[%]
  • Sage
    def A060187(n,k): return sum( (-1)^(k-j)*binomial(n, k-j)*(2*j-1)^(n-1) for j in (1..k) )
    def A178122(n,k): return A060187(n+1, k+1) + 2*binomial(n, k) - 2
    flatten([[A178122(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 18 2022

Formula

T(n, m) = A060187(n+1,m+1) + 2*A007318(n,m) - 2.
T(n, m) = T(n, n-m).
Sum_{k=0..n} T(n, k) = A000165(n) + 2*(2^n -(n+1)).

Extensions

Indices in definition corrected, row sum formula added by the Assoc. Eds. of the OEIS - Aug 20 2010