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.

A258290 Arithmetic derivative of central binomial coefficients, cf. A000984.

Original entry on oeis.org

0, 1, 5, 24, 59, 456, 1448, 6868, 19749, 69364, 236356, 1526956, 3717440, 22858340, 122553540, 474051984, 954720543, 5726109024, 19329586520, 92051285020, 319059863484, 1271796704788, 4829219746964, 29791326914640, 74372011398840, 340296661452300
Offset: 0

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Author

Reinhard Zumkeller, May 26 2015

Keywords

Crossrefs

Programs

  • Haskell
    a258290 = a003415 . a000984
  • Mathematica
    ad[n_] := n * Plus @@ ((Last[#]/First[#]) & /@ FactorInteger[n]); ad[0] = ad[1] = 0; a[n_] := ad[Binomial[2*n, n]]; Array[a, 26, 0] (* Amiram Eldar, Apr 13 2025 *)

Formula

a(n) = A003415(A000984(n)).
Central terms in triangle A258197: a(n) = A258197(2*n,n).