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.

A294790 Subtract n from partial sums of partial sums of Catalan numbers.

Original entry on oeis.org

1, 2, 5, 13, 35, 99, 295, 920, 2975, 9892, 33605, 116104, 406615, 1440026, 5147877, 18550573, 67310939, 245716095, 901759951, 3325066997, 12312494463, 45766188949, 170702447075, 638698318851, 2396598337951, 9016444758503, 34003644251207, 128524394659915
Offset: 0

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Author

Eric M. Schmidt, Nov 08 2017

Keywords

Crossrefs

Cf. A014140. - Michael De Vlieger, Oct 01 2019

Programs

  • Maple
    a:= proc(n) option remember; `if`(n<3, 1+n^2,
         (6*n*a(n-1)-(9*n-3)*a(n-2)+(4*n-2)*a(n-3))/(n+1))
        end:
    seq(a(n), n=0..30);  # Alois P. Heinz, Oct 01 2019
  • Mathematica
    MapIndexed[#1 - First[#2] + 1 &, CoefficientList[Series[1/(1 - x)^2*(1 - Sqrt[1 - 4 x])/(2 x), {x, 0, 27}], x]] (* Michael De Vlieger, Oct 01 2019 *)

Formula

a(n) = A014140(n) - n.