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 1-2 of 2 results.

A188588 Row sums of 1-Euler triangle A188587.

Original entry on oeis.org

1, 2, 3, 12, 60, 360, 2520, 20160, 181440, 1814400, 19958400, 239500800, 3113510400, 43589145600, 653837184000, 10461394944000, 177843714048000, 3201186852864000, 60822550204416000, 1216451004088320000, 25545471085854720000
Offset: 0

Views

Author

Paul Barry, Apr 04 2011

Keywords

Crossrefs

Cf. A001710.

Formula

a(n) = (n+1)*A001710(n).
a(n) = (n+1)*a(n-1), n>2.

A188589 Expansion of (1-3*x+6*x^2-3*x^3)/((1-x)^2*(1-2*x)).

Original entry on oeis.org

1, 1, 5, 14, 33, 72, 151, 310, 629, 1268, 2547, 5106, 10225, 20464, 40943, 81902, 163821, 327660, 655339, 1310698, 2621417, 5242856, 10485735, 20971494, 41943013, 83886052, 167772131, 335544290, 671088609, 1342177248, 2684354527
Offset: 0

Views

Author

Paul Barry, Apr 04 2011

Keywords

Comments

Second column of the 1-Euler triangle A188587. In general, the second column of the r-Euler triangle has g.f. (1-(4-r)*x+2*(4-r)*x^2-(4-r)*x^3)/((1-x)^2*(1-2*x)).

Links

Programs

  • Mathematica
    CoefficientList[Series[(1-3x+6x^2-3x^3)/((1-x)^2(1-2x)),{x,0,30}],x] (* or *) LinearRecurrence[{4,-5,2},{1,1,5,14},40] (* Harvey P. Dale, Nov 26 2017 *)
  • PARI
    a(n) = if (n==0, 1, 5*2^(n-1) - n - 3) \\ Michel Marcus, Jul 24 2013

Formula

a(n+1)=A094002(n).
a(n) = 5*2^(n-1)-n-3, n>0.
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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